Waterproof camera having a semi-underwater photographing mode

ABSTRACT

A waterproof camera includes an image pickup section, a display section that displays image data, a mode setting section that sets a semi-underwater mode in which both objects under water and above water are simultaneously photographed, and a display control section that limits a display range of the display section when the semi-underwater mode is set, wherein the mode setting section controls the position of a photographing lens or the like to adjust a focus balance of at least one of under water and above water, and the display control section displays both object images under water and above water within a limited display range of the display section.

CROSS REFERENCE TO RELATED APPLICATION

This application claims benefit of Japanese Application Nos. 2009-207739filed in Japan on Sep. 9, 2009, 2009-217669 filed in Japan on Sep. 18,2009 and 2009-260245 filed in Japan on Nov. 13, 2009 the contents ofwhich are incorporated by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a waterproof camera and a displaymethod, and more particularly, to a waterproof camera and a displaymethod using the waterproof camera capable of photographing under water.

2. Description of the Related Art

Portable devices such as cameras in recent years have improvedwaterproof functions and many cameras which can operate even whendropped into water are provided, and furthermore there are an increasingnumber of cameras that can be used under water. Photographing underwater allows photographs that cannot be observed on land to be taken andthe number of users who enjoy underwater photography is also increasing.

However, when photographs are taken by a waterfront, a greater varietyof photographing will be made possible if it is possible to photographboth under water and above water simultaneously in addition tophotographing under water alone. However, current underwater cameras arenot appropriate for simultaneously photographing both under water andabove water and liquid crystal monitors or the like used during framingon digital cameras have quite poor viewability from above water.

Conventionally, many kinds of methods are proposed air improvingviewability of a display section such as a liquid crystal monitor. Forexample, according to a display control method disclosed in JapanesePatent Application Laid-Open Publication No. 2007-324888, a displaysection detects an amount of external light and highlights a predominantcolor component of a main object when the amount of external light islarge, and thereby improves viewability of the monitor even under highbrightness conditions.

Furthermore, Japanese Patent Application Laid-Open Publication No.2005-328226 discloses a camera that stores color informationcorresponding to a depth of water, changes display color informationaccording to the depth of water, and can thereby visually recognize afocus position and various kinds of information displayed on a monitorscreen satisfactorily even during underwater photographing.

SUMMARY OF THE INVENTION

A waterproof camera according to an embodiment of the present inventionincludes: an image pickup section that converts an object image that haspassed through a photographing lens to image data; a display sectiondisposed on a back side of the waterproof camera body for displaying theimage data converted by the image pickup section; a mode setting sectionthat sets a semi-underwater mode in which both an object under water andan object above water are photographed simultaneously; and a displaycontrol section that controls, when the semi-underwater mode is set, thedisplay section and limits a display range in the display section,wherein the mode setting section controls a position of a photographinglens or the image pickup section and adjusts at least one focus balanceof under water and above water, and the display control sectiondisplays, when photography is performed when the display section isdisposed on an above water and under water border, both the object imageunder water and the object image above water within a limited displayrange of the display section.

A waterproof camera according to another embodiment of the presentinvention includes: an image pickup section that converts an objectimage to image data and outputs the image data; a display section thatdisplays the object image based on the image data; and a displaylimiting section that limits, when an object under water and an objectin air are simultaneously photographed, a display range to a portionwhere the display section is exposed above water.

A waterproof camera according to a further embodiment of the presentinvention includes: an image pickup section that converts an objectimage to image data and outputs the image data; a display section thatdisplays the object image based on the image data; a determining sectionthat determines whether or not a semi-underwater mode is set in whichboth an object under water and an object above water are photographedsimultaneously within a photographing screen of the object image; and anindicator section that causes the display section to display thedetermination result when the semi-underwater mode is set.

A display method according to an embodiment of the present inventionincludes: converting an object image to image data and outputting theimage data, determining whether or not a semi-underwater mode is set inwhich an object under water and an object in air are simultaneouslyphotographed within a photographing screen of the object image, andlimiting a display range in the display section when the semi-underwatermode is set.

A waterproof camera according to a still further embodiment of thepresent invention includes: an image pickup section having aphotographing lens and an image pickup device; a focusing section thatachieves focus on an object image formed on an image pickup plane of theimage pickup device by moving the photographing lens or the image pickupdevice in an optical axis direction of the photographing lens; asemi-underwater photographing mode setting section for setting asemi-underwater photographing mode in which photographing is performedby simultaneously accommodating an object image above water which is anabove water side and an object image under water which is an underwaterside on the image pickup plane; and a focus control section thatcontrols focusing by the focusing section when the semi-underwaterphotographing mode is set so as to obtain a focus position correspondingto a distance from the image pickup section to the object inconsideration of a refractive index under water with respect to theabove water.

A waterproof camera according to a still further embodiment of thepresent invention includes: an image pickup section having aphotographing lens and an image pickup device; a focusing section thatachieves focus on an object image formed on an image pickup plane of theimage pickup device by moving the photographing lens or the image pickupdevice in the optical axis direction of the photographing lens; asemi-underwater photographing mode setting section for setting asemi-underwater photographing mode in which photographing is performedby simultaneously accommodating an object image above water which is anabove water side and an object image under water which is an underwaterside on the image pickup plane; a focus control section that controlsfocusing, by the focusing section when the semi-underwater photographingmode is set so as to obtain a focus position corresponding to a distancefrom the image pickup section to the object in consideration of arefractive index under water with respect to the above water; and anidentification section that identifies between the object image abovewater and the object image under water on the image pickup plane.

A waterproof camera according to a still further embodiment of thepresent invention includes: an image pickup section that converts anobject image that has passed through a photographing lens to image data;a display section provided on a back side of a camera body to display animage of the image data converted by the image pickup section; a modesetting section that controls a position of the photographing lens orthe image pickup section, adjusts a focus balance of at least one ofunder water and above water and sets a semi-underwater mode in whichboth an object under water and an object above water are simultaneouslyphotographed; a detection section that detects, when the semi-underwatermode is set, whether or not a low contrast region having low contrastexists; a recording section that records, when the detection sectiondetects that the low contrast region exists, first and second images inwhich the low contrast region exists respectively; and an imagesynthesis section that synthesizes the first image and the second imagerecorded in the recording section, wherein the image synthesis sectionsynthesizes the low contrast region in the first image with an imageobtained by removing the low contrast region in the second image fromthe second image and generates a synthesized image.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an electrical configuration of acamera according to a first embodiment of the present invention;

FIG. 2A and FIG. 2B are diagrams illustrating a photographed image in asemi underwater mode using the camera according to the first embodimentof the present invention and a diagram illustrating a situation in whicha photographer observes the object on the display section whenphotographing is performed in a semi-underwater mode;

FIG. 3A to FIG. 3D are diagrams illustrating how an object looks on thedisplay section in a case of semi-underwater photography using thecamera according to the first embodiment of the present invention; adiagram illustrating how a light beam travels from the display sectionto the photographer, a diagram illustrating how the display sectionlooks when no particular measures are taken, a diagram illustrating howthe display section according to the present embodiment looks; and adiagram illustrating how the display section in a modification exampleof the present embodiment looks;

FIG. 4 is a diagram illustrating a flowchart of display switchingoperation of the camera according to the first embodiment of the presentinvention;

FIG. 5 is a diagram illustrating a relationship between focus positionswhen simultaneously photographing above water and under water portionsusing the camera according to the first embodiment of the presentinvention;

FIG. 6A and FIG. 6B are diagrams illustrating focus adjustment in thecamera according to the first embodiment of the present invention; across-sectional view illustrating how the photographing lens is let outfrom a focus position of an object above water and a cross-sectionalview illustrating how the focus is further narrowed down from FIG. 6A;

FIG. 7A to FIG. 7C are diagrams illustrating how an object looks on thedisplay section in the case of semi-underwater photography using acamera according to a second embodiment of the present invention; adiagram illustrating a photographed image, a diagram illustrating howthe display section looks and a diagram illustrating a modificationexample showing how the display section looks;

FIG. 8 illustrates a flowchart illustrating a display switchingoperation of the camera according to the second embodiment of thepresent invention;

FIG. 9A and FIG. 9B are diagrams illustrating an appearance and aphotographing state of a camera according to a third embodiment of thepresent invention; an outline perspective view viewed from a front sideand an outline perspective view viewed from a back side;

FIG. 10A and FIG. 10B are diagrams illustrating a photographingsituation using the camera according to the third embodiment of thepresent invention; a diagram illustrating a situation in which aphotographer goes into water to perform photographing in asemi-underwater mode and a diagram illustrating a situation in which thephotographer is photographing in the semi-underwater mode from land;

FIG. 11A to FIG. 11D are diagrams illustrating a display in asemi-underwater mode using the camera according to the third embodimentof the present invention; an outline perspective view of the cameraviewed form the front side, a diagram illustrating a photographingstate, a diagram illustrating a display state in the display section anda diagram illustrating an instruction in a non-display region of anobject image;

FIG. 12 illustrates a flowchart illustrating a display switchingoperation of the camera according to the third embodiment of the presentinvention;

FIG. 13A to FIG. 13E are diagrams illustrating a display in asemi-underwater mode of a camera according to a fourth embodiment of thepresent invention; an outline perspective view of the camera held upsidedown and viewed from an upper front angle, a diagram illustrating aphotographing state, a diagram illustrating a display state in thedisplay section, a diagram illustrating a display example of watersurface guideline in the display section and a diagram illustratinganother display example of water surface guideline in the displaysection;

FIG. 14 is a flowchart illustrating an automatic mode switchingoperation of the camera according to the fourth embodiment of thepresent invention;

FIG. 15 is a diagram illustrating a situation in which the photographeris photographing an object in a semi-underwater state to automaticallyset a semi-underwater mode using a camera according to a fifthembodiment of the present invention;

FIG. 16 is a diagram illustrating an image when taking a photograph in asemi-underwater mode using the camera according to the fifth embodimentof the present invention;

FIG. 17 is a flowchart illustrating a semi-underwater determiningoperation using the camera according to the fifth embodiment of thepresent invention;

FIG. 18 is a flowchart illustrating a display switching operation usingthe camera according to the fifth embodiment of the present invention;

FIG. 19 is a diagram illustrating a state in which the camera accordingto the fifth embodiment of the present invention is used, showing adisplay example indicating that a semi-underwater mode is set;

FIG. 20A to FIG. 20C are diagrams illustrating a state in which thecamera according to the fifth embodiment of the present invention isused; a diagram illustrating a case where the camera is not inclined, adiagram illustrating a case where the camera is inclined forward and adiagram illustrating a case where the camera is inclined backward;

FIG. 21 is a block diagram illustrating a configuration of a cameraaccording to a sixth embodiment of the present invention;

FIG. 22A is a perspective view illustrating a configuration of the frontside of the camera;

FIG. 22B is a perspective view illustrating a configuration of the backside of the camera;

FIG. 23A is a diagram illustrating an object straddling above water andunder water;

FIG. 23B is a diagram illustrating a situation in a semi-underwaterphotographing mode in which the user is simultaneously photographingboth parts of the object straddling above water and under water shown inFIG. 23A using the camera;

FIG. 24 is a diagram illustrating a state of the display section of thecamera and the like in a semi-underwater photographing mode;

FIG. 25A is a diagram illustrating an example of how an image looks onthe display section according to the sixth embodiment;

FIG. 25B is a diagram illustrating another example of how an image lookson the display section according to the sixth embodiment;

FIG. 25C is a diagram illustrating a typical example of how an imagelooks on the display section according to a conventional example;

FIG. 26 is a flowchart illustrating display processing when the displayin FIG. 25A and FIG. 25B is performed;

FIG. 27 illustrates focusing according to the sixth embodiment;

FIG. 28A is a diagram illustrating a focusing operation in asemi-underwater photographing mode according to the sixth embodiment;

FIG. 28B is a diagram illustrating the focusing operation in FIG. 28Awith the focus further narrowed down;

FIG. 29 is a flowchart illustrating a focusing processing procedureaccording to the sixth embodiment;

FIG. 30 is a flowchart illustrating a processing procedure for aphotographing operation by an image processing & control sectionaccording to the sixth embodiment;

FIG. 31 is a block diagram illustrating a configuration of a cameraaccording to a seventh embodiment of the present invention;

FIG. 32A is a perspective view illustrating a configuration of the frontside of the camera according to the seventh embodiment;

FIG. 32B is a perspective view illustrating a configuration of the backside of the camera according to the seventh embodiment;

FIG. 33 is a diagram illustrating a situation in which semi-underwaterphotographing is performed by immersing substantially half thephotographing lens of the camera according to the seventh embodiment inwater;

FIG. 34 is a diagram illustrating an example of photographed imageobtained through the semi-underwater photographing in FIG. 33;

FIG. 35A is a diagram illustrating a posture of the front side of thecamera set when the semi-underwater photographing in FIG. 33 isperformed;

FIG. 35B is a diagram illustrating a posture or the like of the backside of the camera set when the semi-underwater photographing in FIG. 33is performed;

FIG. 36 is a flowchart illustrating a processing procedure for displayswitching;

FIG. 37A is a diagram illustrating a situation in which photographing isperformed by setting a semi-underwater photographing mode when there isa wave greater than the photographing lens diameter;

FIG. 37B is a diagram illustrating a situation in which thephotographing state has changed from that in FIG. 37A due to atemporally fluctuating wave in a state similar to that in FIG. 37A;

FIG. 38A is a diagram illustrating an example of image photographed inthe state shown in FIG. 37A;

FIG. 38B is a diagram illustrating an example of image photographed inthe state shown in FIG. 37B;

FIG. 39 is a flowchart illustrating a processing procedure for aphotographing operation by the image processing & control sectionaccording to the seventh embodiment;

FIG. 40A is a flowchart illustrating an example of the processingprocedure for the processing of determining the semi-underwaterphotographing mode in FIG. 39;

FIG. 40B is a diagram illustrating a typical example of thesemi-underwater photographing mode;

FIG. 40C is a flowchart illustrating an example of the processingprocedure for the processing of determining a second semi-underwaterphotographing mode in FIG. 39;

FIG. 41 is a diagram illustrating an example of use with a cellularphone in a modification example of the seventh embodiment;

FIG. 42 is a diagram illustrating an example of image displayed on thedisplay section when the semi-underwater photographing mode is set inthe case of FIG. 41;

FIG. 43 is a flowchart illustrating a processing procedure fordetermining a semi-underwater photographing mode and a secondsemi-underwater photographing mode in a modification example;

FIG. 44 is a flowchart illustrating a processing procedure whenperforming a control operation according to an identification result byan identification section;

FIG. 45 is a block diagram illustrating a configuration of a cameraaccording to an eighth embodiment of the present invention;

FIG. 46A and FIG. 46B are perspective views illustrating configurationsof the front side and the back side of the camera;

FIG. 47A is a diagram illustrating an object straddling above water andunder water;

FIG. 47B is a diagram illustrating a situation in a semi-underwaterphotographing mode in which the user photographs both parts of theobject straddling above water and under water shown in FIG. 47Asimultaneously using the camera;

FIG. 48 is a diagram illustrating a case where focusing in asemi-underwater photographing mode is performed;

FIG. 49 is a diagram illustrating an operation when focusing is actuallyperformed in a semi-underwater photographing mode according to theeighth embodiment;

FIG. 50 is a flowchart illustrating a processing procedure when thefocusing shown in FIG. 49 is performed;

FIG. 51 is a diagram illustrating a situation in which an originalobject image to be photographed is not formed due to a disturbed watersurface portion when there is a wave whose water surface locallyfluctuates;

FIG. 52A is a diagram illustrating a situation in which photographing isperformed in a semi-underwater photographing mode when there is a wavegreater than the diameter of the photographing lens;

FIG. 52B is a diagram illustrating a photographing state which has beenchanged from that in FIG. 52A due to a temporally fluctuating wave in astate similar to that in FIG. 52A;

FIG. 53A is a diagram illustrating an example of image photographed inthe state in FIG. 52A;

FIG. 53B is a diagram illustrating an example of image photographed inthe state in FIG. 52B;

FIG. 53C is a diagram illustrating an example of synthesized imagegenerated by the image synthesis section according to the eighthembodiment;

FIG. 54 is a flowchart illustrating an example of processing procedurewhen performing photographing by the image processing & control sectionaccording to the eighth embodiment;

FIG. 55 is a flowchart illustrating a processing procedure for detectinga water surface pattern in FIG. 54;

FIG. 56 is a flowchart illustrating a processing procedure fordetermining whether or not the photographing state is in thesemi-underwater photographing mode in FIG. 54;

FIG. 57A to FIG. 57D are diagrams illustrating the processing procedurein FIG. 56;

FIG. 58 is a flowchart illustrating a processing procedure when displayswitching corresponding to the determination result in FIG. 56 isperformed;

FIG. 59A is a flowchart illustrating a processing procedure fordetermining whether or not the photographing state is in thesemi-underwater photographing mode in FIG. 56 in a modification example;

FIG. 59B is a diagram illustrating a typical object corresponding to asemi-underwater photographing mode;

FIG. 60 is a block diagram illustrating a configuration of a portablecamera section of a cellular phone according to a ninth embodiment ofthe present invention;

FIG. 61 is a diagram illustrating a situation in which the user ispicking up and appreciating an image of a turtle in a pond using acellular phone;

FIG. 62A to FIG. 62C are diagrams illustrating an example of imageacquired at different timings in FIG. 61;

FIG. 63 is a flowchart illustrating an example of processing procedurewhen making an appreciation through the image processing & controlsection according to the ninth embodiment;

FIG. 64 is a timing chart thr illustrating an operation corresponding toFIG. 63;

FIG. 65A is a flowchart illustrating part of a processing procedure whendisplay and photographing/recording are performed in conjunction witheach other; and

FIG. 65B is a flowchart illustrating part of the processing procedurewhen a synthesized image is also photographed/recorded.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed using a digital camera to which the present invention isapplied according to the accompanying drawings.

A waterproof camera (hereinafter simply abbreviated as “camera”according to a preferred embodiment of the present invention is providedwith a waterproof mechanism and a camera function thereof operates evenwhen immersed in water without the camera body being impregnated withwater.

Furthermore, the camera is provided with an image pickup section, andthe image pickup section converts an object image to image data anddisplays a live view of the object image on a display section disposedon the back side of the body based on the converted image data. Aphotographer determines a composition and a shutter chance by observinga live view display. During a release operation, image data such asstill images and moving images are recorded in a recording medium andinformation such as a photographing date and time, photographing mode isalso recorded together at this moment. Furthermore, a photographed imagerecorded in the recording medium can be reproduced and displayed on thedisplay section when a reproducing mode is selected.

First Embodiment

FIG. 1 is a block diagram illustrating an electric circuit of a camera10 according to a first embodiment of the present invention. The camera10 is a digital camera and made up of a control section 1, an imagepickup section 2, a recording section 4, an operation determiningsection 6, an acceleration detection section 7, a display section 8 anda clock section 9 or the like. The image pickup section 2 includes aphotographing lens (zoom lens) having a zoom function, an exposurecontrol section such as a shutter/diaphragm, an image pickup device,driving and successive output circuits for the image pickup device orthe like, converts the object image formed by the photographing lens toimage data through the image pickup device and outputs the image data.Furthermore, the image pickup section 2 is also provided with a focusingmechanism for the photographing lens and performs automatic focusingbased on a control signal from the image processing and control section1.

The control section 1 controls an entire sequence of the camera 10according to a program stored in a storage section (not shown). Theimage processing and control section 1 is provided with an imageconversion section 1 a and a display control section 1 b. The imageconversion section 1 a performs image processing such as converting theimage data outputted from the image pickup section 2 to image data of areduced image or changing a vertical/horizontal ratio of an image, thatis, an aspect ratio. Furthermore, the display control section 1 bcontrols a display range when displaying an image on the display section8 based on the image data. In the present embodiment, when asemi-underwater mode is set as will be described later, the displayrange is limited to the upper half portion of the display screen of thedisplay section 8 and no image is displayed on the lower half portionthereof but the display control section 1 b performs display control inthis case as well.

In addition, the image processing and control section 1 incorporates theimage data outputted from the image pickup section 2, performs varioustypes of image processing such as thinning processing, resizeprocessing, cut-out processing, edge enhancement, color correction,image compression, and performs image processing for recording stillimages and moving images in the recording section 4 and forreproducing/displaying still images and moving images. Furthermore, theimage processing and control section 1 extracts a high frequencycomponent of image data inputted from the image pickup section 2 andperforms automatic focusing by adjusting the position of thephotographing lens of the image pickup section 2 so that the highfrequency component reaches a peak value.

The operation determining section 6 determines the states of operationby the user of operation members such as a power supply button, arelease button, a reproducing button, a mode button and outputs thedetermination result to the image processing and control section 1. Theaforementioned image processing and control section 1 controlsphotographing and reproduction in a predetermined sequence according tooperation states of the operation members. A semi-underwater mode can beout using the mode button. The semi-underwater mode is a mode in whichwhen the camera 10 is on the border between above water and under water,both parts of the object under water and above water are simultaneouslyphotographed.

The acceleration detection section 7 has a 6-axis sensor or the like,detects three axial directions and acceleration around three axes or thelike of the camera 10, detects a gravity direction, and thereby alsodetects a posture of the camera 10. Camera shake or the like iscorrected based on a detection output of the acceleration detectionsection 7. When a photographing instruction is given by the releasebutton, the recording section 4 records still images and image dataacquired by the image pickup section 2 and subjected to compressionprocessing by the image processing and control section 1. The clocksection 9 performs a timing operation and outputs photographing date andtime information. The photographing date and time information isrecorded together when image data of still images and moving images isrecorded in the recording section 6.

The display section 8 has a display section such as a liquid crystalpanel disposed on the back side of the camera 10 and displays a liveview prior to photographing, performs normal reproduction/display ofrecorded images or displays camera information or the like. Thephotographer can observe the live view display and determine acomposition and timing. When the semi-underwater mode is selected, theportion of the display screen of the display section 8 corresponding tothe part under water is hard to be seen from above water due to thecontrol of the display control section 1 b, and therefore nothing isdisplayed in this portion.

A photographing lens 2 a (see FIG. 3A) of the camera 10 according to thepresent embodiment is disposed on the front of the camera body and atsubstantially the center with respect to the center of gravity directionand the display screen of the display section 8 is disposed onsubstantially an entire back side.

Next, photographing in a semi-underwater mode of the present embodimentwill be described using FIG. 2A to FIG. 3D, FIG. 2B illustrates asituation in which semi-underwater photographing is being performed andFIG. 2A illustrates an image obtained at this moment. In this image,scenery such as a face of an object 23, a ring buoy and a ship isobserved above water and creatures such as fish 24 and turtles and waterplants are observed under water. The present specification refers tophotographing such scenery including both objects above water and underwater as “semi-underwater photographing.”

When performing semi-underwater photographing, a photographer 21generally desires to take a photograph while keeping his/her face out ofwater into air as shown in FIG. 2B. This is because when one takes aphotograph with his/her face submerged in water, one cannot hold his/herbreath for a long time nor concentrate on photographing or when onetakes a photograph carrying an oxygen bomb, one cannot readily enjoyphotographing.

In order to simultaneously photograph both objects under water and abovewater, the photographer (user) 21 needs to submerge the lower halfportion of the photographing lens of the camera 10 below a water surface31 and half of the display screen of the display section 8 is alsosubmerged in water. To avoid this, the display section 8 may be turnedup or a special adapter may be fitted thereto, hut an accessory used forsuch a purpose is not strong enough and it is hard to maintainrobustness.

As a result, photographing is performed with about half of the screen ofthe display section 8 of the camera 10 submerged in water as shown inFIG. 3A. That is, the lower half of the body of the camera 10 is belowthe water surface 31 and the upper half is above the water surface 31.In this case, the lower half of the photographing lens 2 a of the imagepickup section 2 is also below the water surface 31 and the upper halfthereof is above the water surface 31. Moreover, the lower half of thedisplay screen of the display section 8 is below the water surface 31and the upper half thereof is above the water surface 31.

During semi-underwater photographing, when the photographer 21 looks atthe display screen of the display section 8, since the upper half of thescreen is above the water surface 31, light from the display screendirectly enters eyes 21 a of the photographer 21. However, light fromthe lower half portion of the display screen is reflected by the watersurface 31 due to a difference in refractive index between water and airand never enters the eyes 21 a of the photographer 21.

Therefore, when attempting to perform semi-underwater photographingusing a camera in the relationship shown in FIG. 3A, that is, a camerain which the display screen of the display section 8 is on the oppositesurface of the photographing lens 2 a and the center of the optical axisof the photographing lens 2 a substantially matches the center of thearea of the screen of the display section 8, if the photographer 21looks at the display screen of the display section 8, the lower portionlooks black as shown in FIG. 3B and the lower portion of the objectimage cannot be observed.

Thus, the present embodiment does not display any object image on thescreen portion of the display section 8 below the water surface 31, thatis, the portion of the display screen submerged in water, but displaysthe entire object image on the display screen above the water surface 31as shown in FIG. 3C. In other words, the present embodiment limits thedisplay range of the display section 8 to the portion above water when asemi-underwater mode is set.

In the example shown in FIG. 3C, the object image is displayed inreduced size while maintaining its aspect ratio, but the presentembodiment is not limited to this, and the object image may also bedisplayed on the screen above the water surface 31 by only reducing thevertical size as shown in FIG. 3D. The present embodiment does notdirectly detect up to which position on the display screen correspondsto the portion under water, and therefore the present embodiment limitsthe display range to the portion substantially above the optical axis ofthe photographing lens.

Next, the operation of the present embodiment will be described using aflowchart shown in FIG. 4. This flow is executed by the image processingand control section 1 based on a program stored beforehand. In an entirecamera control flow, when a display switching flow starts, the imageprocessing and control section 1 first determines whether or not asemi-underwater mode is set based on the determination result by theoperation determining section 6 (S1). In the processing in step S1, theoperation determining section 6 determines whether or not thesemi-underwater mode is set.

When the determination result in step S1 shows that the semi-underwatermode is not set, the display section 8 performs normal display (S10). Inthe processing in step S10, the display control section 1 b performscontrol so that the object image is displayed on the full screen of thedisplay section 8 based on the image data outputted from the imagepickup section 2.

On the other hand, when the determination result in step S1 shows thatthe semi-underwater mode is set, the display control section 1 bperforms control so that the object image is displayed in reduced sizeon the upper half portion of the display screen of the display section 8(S2), here, the image conversion section 1.a generates the reduced imageshown in FIG. 3C or FIG. 3D and the display control section 1 b performscontrol so that the reduced image generated is displayed on the upperhalf portion of the display screen of the display section 8.

After performing the reduced display in step S2 or normal display instep S10, the process returns to an original flow.

Next, automatic focusing in the present embodiment will be describedusing FIG. 5 to FIG. 6B. When a comparison is made between portionsabove water and under water, the photographer cannot continue to holdhis/her breath under water. Furthermore, the position of the camera 10is not stable due to buoyancy, and moreover since fish or the like moveactively, a degree of freedom with respect to automatic focusing ishigher above water. Thus, it is preferable to perform such autofocusthat focusing is preferentially performed on objects above water andfocus on objects under water is also achieved as much as possible.

FIG. 5 illustrates a relationship between focus positions when objectsabove water and under water are simultaneously photographed. A coverglass 2 b, a photographing lens 2 c and an image pickup device 2 dconstitute the image pickup section 2 of the camera 10. Now, suppose acase where an optical axis of the photographing lens 2 c matches thewater surface 31. A light beam 25 a is emitted from the object 23,passes above water, passes through the cover glass 2 b, thephotographing lens 2 c and forms an image on the image pickup device 2d.

When the photographing lens 2 c is located at a position where focus isachieved on the light beam 25 a that has passed above water, a lightbeam 25 c traveling from a place farther than the object 23 throughunder water forms an image on the image pickup device 2 d, whereas alight beam 25 b emitted from the object 23 does not form an image on theimage pickup device 2 d. This is because there is a difference inrefractive index between air (above water) and water (under water).

Therefore, when the photographing lens 2 c is simply focused on theobject 23 above water (focus balance), the object 23 under water looksfrontward due to the refractive index of water, and therefore an objectunder water comes into focus behind the figure object 23. This is notconvenient because the fish 24 in front of the figure object 23 tend notto conic into focus. Moreover, a distant object under water is hardlyphotographed because of transparency of and is not convenient in thatsense either.

Thus, according to the present embodiment, in the case ofsemi-underwater photographing, priority is given to focusing resultsabove water, but the focusing results are not used as they are and thephotographing lens 2 c is designed to move so as to achieve focus at adistance shorter than the focusing result above water as shown in FIG.6A. This makes it possible to achieve focus balance between above waterand under water.

In normal automatic focusing, as described above, the image processingand control section 1 extracts a high frequency component of image dataand adjusts the position of the photographing lens of the image pickupsection 2 so that the high frequency component reaches a peak value.

When the semi-underwater mode is set, the image processing and controlsection 1 detects the position corresponding to the peak value of thehigh frequency component using a luminous flux of the object that haspassed above water, but since this position is a focus positioncorresponding to the object above water, control is performed such thata position to which the lens is moved by a predetermined value from thefocus position is designated as the focusing position.

Furthermore, when the semi-underwater mode is set, a diaphragm 2 e maybe further narrowed down to reduce an amount of blur as shown in FIG.6B. Light quantity decreases by narrowing down the diaphragm, but sincethe amount of blur decreases, it is possible to make a difference in thefocus position under water and above water less obtrusive.

As described above, when the semi-underwater mode is set, the firstembodiment of the present invention does not display the object image onthe lower half portion of the display screen of the display section 8but displays the entire object image on the upper half portion of thedisplay screen. For this reason, the entire object image can berecognized even in the case where the positions of the photographer'seyes are above water.

In the present embodiment, the photographing lenses 2 a and 2 c arelocated on the front of the camera body and at substantially the centerin a longitudinal direction. Furthermore, since the display screen ofthe display section 8 indicates substantially the entire region of theback side of the camera body, when the semi-underwater mode is set, ifthe optical axis of the photographing lenses 2 a and 2 e is made tomatch the water surface 31, substantially the center of the displayscreen corresponds to the water surface. However, there is also a casewhere the position of the photographing lens is not located atsubstantially the center, and in such a case, a limitation may beimposed on the display according to the position of the photographinglens and the display range may be determined.

Second Embodiment

Next, a second embodiment of the present invention will be describedusing FIG. 7A to FIG. 8. The first embodiment displays the entire objectimage in reduced size at a portion above the water surface 31 of thedisplay screen of the display section 8. By contrast, the secondembodiment divides an object image on a portion corresponding to aposition above the water surface 31 or displays the object image underthe water surface without reducing the size of the object.

Like FIG. 2B, FIG. 7A illustrates an image obtained when thephotographer sets the photographing lens so that the optical axisthereof substantially matches the water surface. As in the case of FIG.2A, a photographed image is obtained in which the object 23 is locatedabove and below the water surface 31 and the fish 24 are swimming underwater. When the semi-underwater mode is set, the second embodimentdisplays an image shown in FIG. 7B on the display screen of the displaysection 8.

That is, because the portion is not visible from the photographer due tothe refractive index of water, no object image is displayed in a lowerdisplay screen 8 b which is the lower half portion of the displayscreen. Furthermore, a partial image 33 in FIG. 7A is divided into upperand lower portions, the upper half portion is displayed on an upperportion display screen 8 c which corresponds to a left side of the upperhalf portion and the lower half portion of the partial image 33 isdisplayed on an upper portion display screen 8 d which corresponds to aright side of the upper half portion. Therefore, when the photographerobserves the display screen of the display section 8, the object 23above the water surface and the object 23 below the water surface aredisplayed side by side on the left and on the right respectively.

Furthermore, there is also away of thinking that the entire photographedimage need not always be shown. That is, while the photographer caneasily recognize an object image above the water surface by a naked eye,the photographer cannot recognize an object image below the watersurface by the naked eye, and therefore there is a way of thinking thatonly the object image below the water surface may be displayed on thedisplay screen of the display section 8.

The display shown in FIG. 7C is along the lines of this way of thinking.That is, an underwater object image 34 below the water surface 31 inFIG. 7A is displayed on an upper display screen 8 a as is. In this case,since the object image above the water surface 31 is not displayed onthe display screen of the display section 8, the object image above thewater surface 31 may be obtained by analogy with the underwater imageand roughly estimated by a direct visual check.

Since such a configuration of the present embodiment is substantiallythe same as the block diagram in FIG. 1 described in the firstembodiment, detailed descriptions thereof will be omitted. The imageconversion section 1 a can divide the image based on the image data fromthe image pickup section 2 as shown in FIG. 7B and extract only theimage of the underwater portion as shown in FIG. 7C. The displayswitching operation according to the present embodiment will bedescribed using a flowchart shown in FIG. 8. This flow is executed bythe image processing and control section 1 based on a program storedbeforehand.

In the entire camera control flow, when the display switching flowstarts, it is first determined whether or not a semi-underwater mode isset as in the case of the first embodiment (S1). In the processing instep S1, the operation determining section 6 determines whether or notthe semi-underwater mode is set.

When the determination result in step S1 shows that the semi-underwatermode is not set, the display section 8 performs a normal display as inthe case of the first embodiment (S10). In the processing in step S10,the object image is displayed on the full screen of the display section8 through the control of the display control section 1 b based on theimage data outputted from the image pickup section 2. On the other hand,when the determination result in step S1 shows that the semi-underwatermode is set, the display control section 1 b performs control such thata divided display or only an underwater display is performed on theupper half portion of the screen (S3).

In the processing in this step S3, as described in FIG. 7B, the displaysection 8 displays the divided partial object image 33 on the upperdisplay screen 8 a or displays the underwater object image 34 which onlyexists below the water surface on the upper display screen 8 a asdescribed in FIG. 7C. After performing a normal display in step S10 orafter performing a divided display or only an underwater display in stepS3, the process returns to the original flow.

Thus, when the semi-underwater mode is set, the second embodiment of thepresent invention displays no object image on the lower display screen 8b of the lower half portion of the display section 8, displays a partialimage obtained by dividing a whole object image or only the object imagebelow the water surface on the upper display screen 8 a of the upperhalf portion of the display screen. Thus, it is possible to recognizethe object image without reducing the size of the object image.

Third Embodiment

Next, a third embodiment of the present invention will be describedusing FIG. 9A to FIG. 12. In the first and second embodiments of thepresent invention, the photographing lenses 2 a and 2 c are disposedsubstantially at the center of the front of the camera body and theposition corresponding to the water surface on the display screen of thedisplay section 8 is substantially at the center of the screen. In athird embodiment, the position of photographing lenses 2 a is deviatedfrom substantially the center on the front of the camera body. Thepresent embodiment is designed to provide an optimum display for thecamera.

FIG. 9A is an outline perspective view of the camera 10 according to thepresent embodiment viewed from the front side and FIG. 9B is an outlineperspective view viewed from the hack side. A release button 9 a whichis one of operation members is disposed on the top surface of the bodyof the camera 10. Furthermore, a photographing lens 2 a is disposed on arelatively top right side on the front of the body. Furthermore, astrobe 3 a is disposed on a relatively top left side on the front of thebody. The photographing lens 2 a is a zoom lens and the optical path ofthe zoom lens is folded and accommodated in the camera body.

Furthermore, the display screen of the display section 8 occupies mostor the back side of the camera 10 as shown in FIG. 9B. A mode settingswitch 9 b is disposed on the back side and on one side of the displayscreen of the display section 8.

When performing semi-underwater photographing using the camera 10according to the present embodiment, the photographer goes into water asshown in FIG. 10A and performs photographing in such a way that theoptical axis of the photographing lens 2 a substantially matches thewater surface 31. Furthermore, instead of the photographer going intowater, the photographer may put only the camera 10 into water in such away that the optical axis of the photographing lens substantiallymatches the water surface 31 as shown in FIG. 10B.

When using the camera 10 located as shown in FIG. 9A and FIG. 9B, thecamera 10 is placed in the longitudinal position as shown in FIG. 11Aand substantially half of the photographing lens 2 a is submerged inwater so that photographing is possible with much of the display section8 exposed above water. In this case, photographing can be performed onlyin the longitudinal composition, but when the photographer wants tophotograph objects in a deep part under water, such an arrangement ispreferable.

When the longitudinal position is adopted, much of the display screen ofthe display section 8 can be used, and therefore non-use regions aredetermined with reference to the position of the photographing lens 2 a.That is, as shown in FIG. 11C, a water surface guideline 8 f isdisplayed on the display screen of the display section 8 incorrespondence with the position of the photographing lens 2 a. Supposean upper display screen 8 a above the water surface guideline 8 f is ausable region and a lower display screen 8 b below the water surfaceguideline 8 f is a non-use region. The moving direction of the camera 10is displayed in this non-use region as shown in FIG. 11D to facilitatephotographing in the semi-underwater mode. In the example shown in FIG.11D, the mode is displayed as “semi-underwater model” together with adisplay “immerse in water” and the direction is indicated by a downwardarrow.

Displaying the water surface guideline 8 f and displaying the mode anddirection on the display screen of the display section 8 allows even auser unfamiliar with the method of use of the semi-underwater mode toeasily perform photographing in the semi-underwater mode.

Such a circuit configuration of the present embodiment is substantiallythe same as that in the block diagram in FIG. 1 described in the firstembodiment, and therefore detailed descriptions thereof will be omitted.In the first embodiment, the display control section 1 b sets thelimitation range within which the object image is displayed in aposition above the center when the camera is placed in the lateralposition, but in the present embodiment, the display control section 1 bsets the limitation range in a position above the position of thephotographing lens 2 a when the camera is placed in the longitudinalposition.

The display switching operation according to the present embodiment willbe described using a flowchart shown in FIG. 12. This flow is executedby the image processing and control section 1 based on a program storedbeforehand as in the case of the first and second embodiments. In theentire camera control flow, when the display switching flow starts, itis first deter mined whether or not a semi-underwater mode is set as inthe case of the first embodiment (S1). In the processing in step S1, theoperation determining section 6 determines whether or not asemi-underwater mode is set.

When the determination result in step S1 shows that the semi-underwatermode is not set, the display section 8 performs a normal display as inthe case of the first embodiment (S10). In the processing in step S10,the display control section 1 b performs control so that an object imageis displayed on the full screen of the display section 8 based on imagedata outputted from the image pickup section 2. On the other hand, whenthe determination result in step S1 shows that the semi-underwater modeis set, the display section 8 displays a live view in an above-water useregion of the screen (S4).

In the processing in this step S4, as described using FIG. 11C, a liveview is displayed in a region of the upper display screen 8 a, that is,a use region based on the image data from the image pickup section 2.Next, the display section 8 displays a mode, a direction and a watersurface guideline in the non-use region under the control of the displaycontrol section 1 b (S5). In this step S5, as described using FIG. 11C,a mode display “semi-underwater mode” and a direction display using anarrow and “immerse in water” are shown in the region of the lowerdisplay screen 8 b, that is, the non-use region and the display section8 displays the water surface guideline 8 f. After performing a normaldisplay in step Sit) or after performing a display in step S5, theprocess returns to the original flow.

Thus, according to the third embodiment of the present invention, whenthe photographing lens 2 a is not disposed substantially at the centerof the camera body, the display screen exposed above water can beeffectively used. Furthermore, displaying the water surface guideline 8f makes it possible to efficiently position the camera 10 and speedilyperform photographing in a semi-underwater mode.

Fourth Embodiment

Next, a fourth embodiment of the present invention will be describedusing FIG. 13A to FIG. 14. The third embodiment uses the display screenin the longitudinal position, whereas the fourth embodiment uses thedisplay screen in the lateral position. Furthermore, the first to thirdembodiments manually set the semi-underwater mode, but the presentembodiment automatically sets the semi-underwater mode.

An outline view of the camera 10 according to the present embodiment issimilar to that in FIG. 9, but when performing semi-underwaterphotographing, the camera 10 is used upside down as shown in FIG. 13A,FIG. 13A is an outline perspective view of the camera 10 when the camera10 is held upside down and viewed from the front angle and FIG. 13C isan outline perspective view of the camera viewed from the back side.

When the photographer puts the camera 10 upside down, the photographinglens 2 a is positioned on the relatively lower left side of the front ofthe body and a strobe 3 a is positioned on the relatively lower rightside of the front of the body. The light-emitting position of the strobe3 a is lower than the photographing lens 2 a. Setting such alight-emitting position causes most of strobe light to be projected intowater and can thereby give sufficient illumination to an object underwater.

Furthermore, the display screen of the display section 8 occupies mostof the back side of the camera 10 as shown in FIG. 13C. A mode settingswitch 9 b is disposed on one side of the display screen of the displaysection 8 on the back side.

When semi-underwater photographing is performed using such a camera 10of the present embodiment, the photographer goes into water as shown inFIG. 13B and sets the camera so that the optical axis of thephotographing lens 2 a substantially matches the water surface 31. Itgoes without saying that instead of the photographer going into water,the photographer may put only the camera 10 into water and set thecamera so that the water surface 31 substantially matches the opticalaxis of the photographing lens as shown in FIG. 10B.

When the camera 10 in such an arrangement is used, the camera 10 isplaced in the lateral position as shown in FIG. 13B, substantially halfthe photographing lens 2 a is submerged in water and it is therebypossible to perform photographing with much of the display section 8exposed above water. Here, however, only upside-down composition can bephotographed in this case, but there is a merit of being able to use awide area of the screen above water as shown in FIG. 13C. Furthermore,since the release button 9 a is on the opposite side, the releaseoperation is not easy. To solve this problem, when the semi-underwatermode is set, the setting may be changed so that another switch such asthe mode setting switch 9 b can be used as the release button.

Setting the camera in the lateral position allows the wide area of thedisplay screen of the display section 8 to be used, and therefore anon-use region is determined with reference to the position of thephotographing lens 2 a as in the case of the third embodiment. That is,as shown in FIG. 13C, the display control section 1 b displays a watersurface guideline 8 f on the display screen of the display section 8 incorrespondence with the position of the photographing lens 2 a. An upperdisplay screen 8 a above the water surface guideline 8 f is set as ausable region and a lower display screen 8 b below the water surfaceguideline 8 f is set as a non-use region.

As in the case of the third embodiment, the display section 8 displaysthe mode (here, displayed as “semi-underwater mode”) and displays themoving direction of the camera 10 using an arrow in a non-use region. Inaddition to the straight line shown in FIG. 13D used as the watersurface guideline 8 f, a waveform water surface guideline 8 f′ may alsobe displayed as shown in FIG. 13E. Displaying the water surfaceguideline 8 f with a waveform rather than a straight line helps the userintuitively identify it as the water surface.

Since such a circuit configuration of the present embodiment issubstantially the same as that of the block diagram in FIG. 1 describedin the first embodiment, detailed descriptions thereof will be omitted.With the camera disposed upside down, the display control section 1 blimits the display range to the area above the photographing lens 2 a.Unlike the first to third embodiments, in the operation of the displayswitching of the present embodiment, display switching is performedautomatically. This automatic mode will be described using a flowchartshown in FIG. 14. As in the case of the first to third embodiments, thisflow is executed by the image processing and control section 1 based ona program stored beforehand.

In the entire camera control flow, when an automatic mode flow starts,the image processing and control section 1 first determines whether ornot the posture of the camera is inverted (S21). In the fourthembodiment, when semi-underwater photographing is performed, thephotographer puts the camera 10 upside down as shown in FIG. 13A, andtherefore in this step S21, the acceleration detection section 7 detectsand determines the posture of the camera 10.

As a result of the determination in step S21, if the posture of thecamera is not inverted, the display section 8 performs a normal displayas in the case of the first embodiment (S24). In this step S24, thedisplay control section 1 b performs control so that an object image isdisplayed on the full screen of the display section 8 based on imagedata outputted from the image pickup section 2. On the other hand, ifthe posture of the camera is inverted as a result of the determinationin step S21, a semi-underwater mode is set (S22). Here, asemi-underwater mode is automatically set as the photographing mode ofthe camera 10.

Next, the release function is switched to the mode setting switch 9 b(S23). As described above, when the photographer uses the camera 10 inan upside-down position, the position of the release button 9 a isinverted and it becomes difficult to use the release button 9 a.Therefore, the image processing and control section 1 controls switchingof the function so that the mode setting switch 9 b can be used as therelease button. After performing the processing in step S23 or step S24,the process returns to the original flow.

Thus, according to the fourth embodiment of the present invention, whenthe photographing lens 2 a is not disposed substantially at the centerof the camera body of the camera 10, the display screen exposed abovewater can be effectively used. Furthermore, by detecting the inversionof the posture of the camera 10, it is possible to automatically switchthe mode to the semi-underwater mode and omit a troublesome switchingoperation.

The third embodiment and the fourth embodiment display the mode display,mode direction and water surface guideline in the non-use region, butall of these items need not be displayed. Furthermore, although thethird embodiment and the fourth embodiment have been described asdifferent embodiments, the basic configuration of the camera 10 is thesame, and therefore it may also be possible to detect the posture of thecamera by the acceleration detection section 7 and operate the camera inthe semi-underwater mode corresponding to the longitudinal position orlateral position depending on the detection result.

Fifth Embodiment

Next, a fifth embodiment of the present invention will be describedusing FIG. 15 to FIG. 20C. The first to fourth embodiments manually setthe semi-underwater mode, whereas the present embodiment automaticallysets a semi-underwater mode in the case of a state appropriate tosemi-underwater photographing. The method of determining whether or notthe camera is in a semi-underwater state in the present embodiment willbe described using FIG. 15 and FIG. 16.

FIG. 15 shows a situation in which the photographer 21 takes asemi-underwater photograph of a turtle 26 which shows its head out ofthe water or a water plant 27 under water using the camera 10 and FIG.16 is a photographed image in this case. The water surface 31 isactually swaying and the water surface portion does not form a straightline as shown in FIG. 16 and the boundary section has a hand-like shape(see a boundary hand 28 in FIG. 16).

Therefore, it is possible to determine the presence/absence of asemi-underwater state by detecting a low contrast portion with no imageas the boundary band 28. That is, whether or not a low contrast portionextends in a band shape may be determined based on image data outputtedfrom the image pickup section 2 of the camera 10. In this case, theacceleration detection section 7 determines whether the camera 10 is ina longitudinal position or a lateral position, and the accelerationdetection section 7 determines that the camera 10 is in thesemi-underwater state when the camera 10 is in the lateral position, ifa hand-shaped low contrast portion crosses the screen in thelongitudinal direction of the photographing screen or when the camera 10is in the longitudinal position, if a band-shaped low contrast portioncrosses the screen in the direction perpendicular to the longitudinaldirection of the photographing screen.

When the camera 10 is in a semi-underwater state, the present embodimentautomatically sets the semi-underwater mode based on the aforementionedconcept. Thus, since the circuit configuration of the present embodimentis substantially the same as that of the block diagram in FIG. 1described in the first embodiment, detailed descriptions thereof will beomitted.

The semi-underwater determining operation of determining whether or nota semi-underwater state is set according to the present embodiment willbe described using a flowchart shown in FIG. 17. This flow is executedby the image processing and control section 1 based on a program storedbeforehand as in the case of the first to fourth embodiments.

In the entire camera control flow, when a semi-underwater determiningflow starts, the image processing and control section 1 first determineswhether or not there is a low contrast region in the center portion ofthe screen (S31). Here, the image processing and control section 1determines based on image data from the image pickup section 2 whetheror not the center portion of the screen is in low contrast. Low contrastis determined by detecting whether or not there is a change betweenneighboring pixels and detecting that the change is small.

A case has been described where the screen width is assumed to be, forexample, 10 and the ratio of occupation by under water and above waterparts is assumed to be 5:5, but the present invention is not limited tothis, and since photographing may be performed with other compositionthan 5:5, for example, a case with under water being 3 and above waterbeing 7 or contrarily a case with under water being 7 and above waterbeing 3, the region which is detected to be a low contrast or not mayhave a degree of freedom so as to support these cases.

As a result of the determination in step S31, if there is a low contrastregion in the center portion of the screen, the image processing andcontrol section 1 determines above water or under water next (S32). Thisprocessing is performed by determining whether the camera 10 is in alateral position or in a longitudinal position based on the output ofthe acceleration detection section 7.

When above water or under water is determined, the image processing andcontrol section 1 then determines whether or not the low contrast regioncrosses the screen in a band shape (S33). As described above, when thecamera 10 is in the lateral position, the image processing and controlsection 1 determines whether or not the band-shaped low contrast regionextends in the longitudinal direction of the screen. Furthermore, whenthe camera 10 is in the longitudinal position, the image processing andcontrol section 1 determines whether or not the band-shaped low contrastregion extends in the direction orthogonal to the longitudinal directionof the screen.

As a result of the determination in step S33, if the low contrast regioncrosses the screen in a band shape, the image processing and controlsection 1 then determines whether or not the camera 10 has tipped over(S34). When photographing is performed in a semi-underwater state, ifthe optical axis of the photographing lens 2 a does not match orsubstantially parallel the water surface 31 as shown in FIG. 20A, thearrangement of the object under water and above water is not in a goodcondition. That is, if the photographing lens 2 a is inclined downwardas shown in FIG. 20B, the object under water occupies most of thescreen, while if the photographing lens 2 a is inclined upward as shownin FIG. 20C, the object above water occupies most of the screen. Thus,in step S34, the image processing and control section 1 determineswhether or not the camera 10 has tipped over (inclined) based on thedetection result of the acceleration detection section 7.

As a result of the determination in step S34, if the camera has nottipped over, the image processing and control section 1 then determineswhether or not focus is achieved at a short distance (S35). Focusing ofthe photographing lens 2 a is performed based on image data from theimage pickup section 2, through so-called contrast AF.

In this step S35, the image processing and control section 1 detects thedistance of the object subjected to the focusing through contrast AF anddetermines whether or not the distance is short, for example, close to 1m. This is because light attenuates under water, an object located at along distance appears dark as the object image and the semi-underwatermode is not set in the case of such a long distance.

As a result of the determination in step S35, if focus is achieved at ashort distance, the image processing and control section 1 determinesthe camera to be semi-underwater (S36). From steps S31 to S35, there isa band-shaped low contrast region crossing the center portion of thescreen, and the optical axis of the photographing lens 2 a of the camera10 substantially matches or parallels the water surface 31 and furtherfocus is achieved at a short distance, and therefore the camera 10 isappropriate for semi-underwater photographing. Thus, in this step S36,the state is determined to be semi-underwater. After determining thatthe state is semi-underwater, the process returns to the main flow.

If the result of the determination in any one of steps S31, S33, S34 andS35 is NO, the image processing and control section 1 does not determinethat the state is semi-underwater (S37). If the result of thedetermination in any one of steps S31. S33, S34 and S35 is NO,semi-underwater photographing is not appropriate, and therefore theimage processing and control section 1 does not determine that the stateis semi-underwater. After determining that the state is notsemi-underwater, the process returns to the main flow.

Next, the display switching operation according to the presentembodiment will be described using the flowchart shown in FIG. 18. Inthe entire camera control flow, when the display switching flow starts,the image processing and control section 1 first determines whether ornot the state is semi-underwater (S41). Since whether or not to setsemi-underwater has been determined in aforementioned step S36 or S37,the determination in step S41 is made according to this determination.

As a result of the determination in step S41, if the state issemi-underwater, the display section 8 then displays the mode in theupper half portion of the display section 8 (S42). Here, as shown inFIG. 19, a mode display “this is semi-underwater” is performed in theupper half portion of the display section 8 of the camera 10. Instead ofthis display, another expression such as “semi-underwater mode” may alsobe displayed or an icon or symbol may, of course, be displayed.Furthermore, after performing the mode display or while performing themode display, the object images under water and above water aredisplayed in the portion exposed above water of the display section 8 asdescribed in the first to fourth embodiments.

As a result oldie determination in step S41, if the state is notsemi-underwater, the display section 8 performs a normal display as inthe case of step S10 in FIG. 4 (S43). In this step S43, the object imageis displayed on the full screen of the display section 8 based on imagedata outputted from the image pickup section 2. After performing thedisplay in step S42 or S43, the process returns to the main flow.

Thus, when a state appropriate for semi-underwater photographing is set,the filth embodiment of the present invention automatically sets asemi-underwater mode and displays the object images under water andabove water in an easy-to-see way. This feature is convenient becausethe mode is automatically set without bothering to set thesemi-underwater mode. It is determined based on image data whether ornot the state is semi-underwater and there is no need to particularlyprovide a sensor to determine whether or not the state issemi-underwater.

The present embodiment determines in steps S31 to S35 whether or not thestate is semi-underwater, but such a determination may also be made witha time variation taken into consideration such as using information oncamera shake and a positional relationship of the low contrast region orthe like. When there is an angle variation of the camera due to camerashake, if a low contrast band-shaped pattern varies together with camerashake, this may be interpreted that the water surface is detected. Whena scene of sky with no contrast or the like is photographed, there canbe a low contrast region, but since the shape pattern such as the widthof the band of the low contrast region never changes together withcamera shake in this case, the low contrast region can be distinguishedfrom the water surface.

Furthermore, the present embodiment determines whether or not thesemi-underwater state is set using image data or the like. However, thepresent invention is not limited to this, and if a sensor or the likecan be added, for example, a water detection sensor may be provided todetect whether or not the water surface 31 matches or parallels theoptical axis of the photographing lens 2 a and automatically set asemi-underwater mode based on the detection result of the sensor.

Furthermore, in the aforementioned first to fourth embodiments thesemi-underwater mode is manually set. However, it may, of course, bepossible to add the semi-underwater determination in the presentembodiment and automatically switch to the semi-underwater mode.

As described above, when the semi-underwater mode is set, theembodiments of the present invention limit the display range on thedisplay section, and therefore when both objects under water and abovewater are simultaneously displayed, objects can be observed more easily.

Although the embodiments of the present invention have described thecase where the display section uses a liquid crystal monitor, thepresent invention is not limited to the liquid crystal monitor, butother monitor displays such as organic EL, may, of course, be used.

Furthermore, although the embodiments of the present invention havedescribed the case where a digital camera is used as an apparatus forphotographing, any type of camera can be used, such as digitalsingle-lens reflex camera, compact digital camera, camera for movingimages such as video camera, movie camera or further a cameraincorporated in a cellular phone, portable information terminal (PDA:Personal Digital Assist), game machine. The present invention isapplicable to any photographing apparatus if such an apparatus allowsunderwater photographing.

The present invention is not limited to the above described embodimentsas they are, but components thereof may be modified and embodied withoutdeparting from the spirit and scope of the embodiments. Moreover,various inventions may be formed by combining a plurality of componentsdisclosed in the above described embodiments as appropriate. Forexample, some of all components disclosed in the embodiments may beremoved. Furthermore, components of different embodiments may becombined as appropriate.

Sixth Embodiment

A camera 51 having a waterproof structure provided with a photographingfunction according to a sixth embodiment of the present invention shownin FIG. 21 has a box shape as shown in FIG. 22A and FIG. 22B. Aphotographing lens 53 a that constitutes an image pickup section 53 forpicking up (photographing) an image of an object is provided near thecenter of the front side of a case 52 having a waterproof structure asan enclosure of this camera 51.

Actually, as shown in FIG. 27, FIG. 28A and FIG. 28B, a cover glass 53 cis disposed before the photographing lens 53 a, which makes itwatertight and protects the photographing lens 53 a. Furthermore, thecover glass 53 c and the photographing lens 53 a are mounted in a lensbarrel (not shown). An image pickup device 53 b such as CCD is disposedat an image forming position of the photographing lens 53 a, and thephotographing lens 53 a and the image pickup device 53 b form an imagepickup section 53 in FIG. 21.

Furthermore, as shown in FIG. 21, the image pickup section 53 can focusan object image formed on the image pickup plane of the image pickupdevice 53 b through a focusing section 53 d. The focusing section 53 dis configured using, for example, a drive section 53 e (see FIG. 27)that moves the photographing lens 53 a in the optical axis direction.

Instead of moving the photographing lens 53 a by the drive section 53 e,the image pickup device 53 b may be configured to move in the opticalaxis direction. Furthermore, although the image pickup section 53 andthe focusing section 53 d are shown as independent bodies in FIG. 21 orthe like, the image pickup section 53 may also be configured to includethe focusing section 53 d.

The image pickup device 53 b of the image pickup section 53 outputs animage pickup signal, which is an object image formed on the image pickupplane and then photoelectrically converted, to an image processing &control section 54 that performs image processing and control shown inFIG. 21.

The image processing & control section 54 performs image processing onthe image pickup signal, generates an image signal for display andoutputs the image signal to a display section 55. The display section 55displays an image corresponding to the inputted image signal for displayon a display screen (also simply referred to as a “screen”).

The image displayed on the display section 55 is an image correspondingto the object image formed on the image pickup plane of the image pickupdevice 53 b and the user observes the image and uses the image to checkwhether or not to be recorded as a photographed image.

Thus, in a normal photographing mode, the image processing & controlsection 54 displays the object image formed on the image pickup plane ofthe image pickup device 53 b on the screen of the display section 55 asa normal image (see FIG. 26).

On the other hand, as will be described later, in a photographing statewhen a semi-underwater photographing mode is set, the user cannotsubstantially observe part of the screen of the display section 55, andtherefore the present embodiment has the function of switching the modeto a display mode which is different from the normal mode to display theimage.

The display section 55 is formed on the hack side of the case 52 asshown in FIG. 22B using, for example, a liquid crystal panel in arectangular size which is slightly smaller than the whole plane.

Furthermore, as shown in FIG. 22A and FIG. 22B, a release button 56 athat performs a photographing operation is provided for example on theright side position of the top surface of the case 52. When thephotographer (user) operates an operation section 56 including therelease button 56 a as shown in FIG. 21, the operation result isdetermined by an operation determining section 57.

The information on the determination result of the operation determiningsection 57 is inputted to the image processing & control section 54. Theimage processing & control section 54 performs control corresponding tothe determination result.

When the operation determining section 57 determines a release operation(photographing instruction operation), the image processing & controlsection 54 records the image picked up by the image pickup section 53 ina recording section 58 as a photographed image.

Furthermore, a mode setting switch 56 h as shown in FIG. 22B is providedas the operation section 56 shown in FIG. 21.

Operating the mode setting switch 56 b, the user can set a photographingmode or a reproducing mode, set a semi-underwater photographing mode,which will be described later, select focusing or a display or the likefrom a switch menu.

The mode setting switch 56 b has the function of a semi-underwaterphotographing mode setting section for setting a semi-underwaterphotographing mode.

In addition to the mode setting switch 56 b that has a plurality ofsetting functions, operation buttons or the like may be provided wherebythe user directly performs various instruction operations. Furthermore,operation buttons may also be provided which independently perform aplurality of functions that can be selected from the mode setting switch56 b.

For example, a semi-underwater photographing mode button may beindependently provided which performs an instruction operation forsetting a semi-underwater photographing mode. FIG. 21 shows an examplewhere a semi-underwater photographing mode button 56 c is provided inthe operation section 56, which has the function as a semi-underwaterphotographing mode setting section.

Furthermore, the present embodiment performs focusing control over animage of an object on the above water side when the semi-underwaterphotographing mode is set, but when the distance to the object on theabove water side is large, the present embodiment provides a conditionwhich gives priority to focusing on the image of the object on theunderwater side in consideration of underwater transparency.

To determine whether or not this condition is met, the operation section56 is provided with a boundary distance setting button 56 d whichchanges/sets the value of a boundary distance Lb corresponding to aboundary in consideration of underwater transparency.

The boundary distance Lb is set to, for example, Lb=3 m as a defaultsetting. The user can change/set the boundary distance Lb to a valuecorresponding to the actual underwater transparency by operating theboundary distance setting button 56 d.

A clock section 59 that outputs information on a clock is connected tothe image processing & control section 54 and when a photographingoperation or the like is performed, the image processing & controlsection 54 adds information on a photographing date and time to an imagerecorded in the recording section 58 and records the information.Furthermore, a strobe apparatus 60 is provided on the front of the case52 as shown in FIG. 22A.

The camera 51 of the present embodiment is intended to be able tosimultaneously and simply photograph objects above water such as theface of a figure, ship and landscape on the above water side and objectstinder water such as part of the figure, fish, turtle, and water planton the underwater side as shown in FIG. 23A. Photographing objects abovewater and objects under water simultaneously is referred to as“semi-underwater photographing.”

According to the present embodiment, when the user performs aninstruction operation using, for example, the semi-underwaterphotographing mode button 56 c, the image processing & control section54 sets the camera 51 in a state in which a semi-underwaterphotographing mode (to perform semi-underwater photographing) is set andthe camera 51 is set to an operation state in the semi-underwaterphotographing mode.

In FIG. 23A or the like, reference character W denotes the watersurface, Wu denotes a portion on the above water side and Wi denotes aportion on the underwater side. Furthermore, reference character Tdenotes an object of a figure straddling above water and under water tobe photographed in the semi-underwater photographing mode (forsimplicity).

In the present embodiment, the image processing & control section 54 inFIG. 21 is configured to have the functions of an image conversionsection 54 a, a display control section 54 b, a focusing control section54 c and a distance conversion section 54 d as will be described so asto be able to attain the above described object.

Furthermore, the image processing & control section 54 is configuredusing, for example, a CPU, and a memory 61 that stores a program toexecute the respective functions is connected to the image processing &control section 54. The memory 61 is made up of a non-volatile memorysuch as flash memory. Furthermore, the image processing & controlsection 54 is internally provided with a memory (not shown) such as RAMto temporarily store data or the like used in executing variousfunctions.

When performing semi-underwater photographing as described above, a user63 can preferably perform a photographing operation by keeping his/herface out of water in air (above water) as shown in FIG. 23B. The user 63may also be able to perform a photographing operation while holdinghis/her breath under water, but the user can hardly concentrate onphotographing, and therefore the user may preferably keep his/her faceabove water to readily enjoy photographing as described above.

In the case of FIG. 23B, nearly half of the display plane of the displaysection 55 on the back side of the camera 51 is submerged below thewater surface (see FIG. 24). In this case, the display section 55 may beplaced face up or a dedicated adapter may be used to prevent the displaysection 55 from being submerged in water. However, if the displaysection 55 is placed face up, the photographing direction of thephotographing lens 53 a on the front side is downward and it isdifficult to perform desired semi-underwater photographing.

Furthermore, a dedicated adapter is not appropriate for applicationswhere semi-underwater photographing is readily performed and it isdifficult to guarantee robustness necessary for the camera 51 used forunderwater photographing.

The camera 51 shown in FIG. 23B is set in a state as shown in FIG. 24.In the state of semi-underwater photographing mode set as shown in FIG.24, about the lower half portion of the photographing lens 53 a on thefront side of the camera 51 is submerged in water and the lower halfportion of the display section 55 is likewise submerged in water.

Since the refractive index of water nw (=1.33) is considerably greaterthan the refractive index of air na (=1), the user 63 cannot view thedisplay image of the portion under water (submerged portion) in thedisplay section 55 in such a state.

That is, most of light on the display section 55 from the underwaterportion is reflected on the water surface as shown in FIG. 24 and doesnot reach the eyes 63 a of the user or deviates from the direction ofthe eyes 63 a (of the user 63) due to refraction (part of the objectnear the water surface may be observed depending on the viewingdirection of the user 63 or may be seen compressed up and down dependingon the angle, but is hard to be seen anyway).

Therefore, when the user views the display image displayed on thedisplay section using a conventional camera, the image actually looks asshown in FIG. 25C. That is, as shown in FIG. 25C, only objects on theabove water side and part of objects near the water surface can beobserved.

Therefore, (with the conventional example camera), there is suchinconvenience that the user cannot observe most of the display imagebelow the vicinity of the surface of water, which constitutes adisadvantage that it is difficult to check the image duringphotographing. To solve such inconvenience, the present embodimentadopts the following configuration.

According to the present embodiment, when a semi-underwaterphotographing mode is set, the image processing & control section 54(image processing section provided therein) shown in FIG. 21 has thefunction of the image conversion section 54 a that converts the imagepicked up by the image pickup section 53 to an image obtained byreducing the longitudinal and lateral sizes (lithe picked up image or animage obtained by reducing (compressing) only the size in thelongitudinal direction.

Furthermore, when a semi-underwater photographing mode is set, the imageprocessing & control section 54 (control section provided therein) hasthe function of the display control section 54 b of performing controlso as to change the display position (display region) when the imagegenerated by the image conversion section 54 a is displayed on thedisplay section 55.

To be more specific, when the semi-underwater photographing mode is set,the display control section 54 b controls display switching so as todisplay the image generated by the image conversion section 54 a in, forexample, substantially the upper half portion of the region of the fullscreen of the display section 55.

FIG. 25A and FIG. 25B illustrate how an image looks when a displayexample on the display section 55 or image displayed on the displaysection 55 according to the present embodiment is actually observed whenthe semi-underwater photographing mode is set.

In this case, image display examples are shown where the picked up imageis reduced to ½ in longitudinal and lateral sizes or reduced to ½ onlyin the longitudinal direction by the image conversion section 54 a.

The present embodiment reduces the size of the picked up image so as tobe displayed on substantially the upper half portion of the screen(region) of the full screen of the display section 55. The objects abovewater and under water reduced in size are accommodated within the upperhalf portion of the screen and displayed. In this case, nothing isdisplayed on the substantially lower half portion of the screen of thedisplay section 55 submerged in water.

In this case, even if there is a region of the screen that cannot beseen even when (the image thereof is) observed because of submersion inwater, the picked up image can be observed without being substantiallyaffected by the screen region. The user 63 can then check the picked upimage corresponding to the object image formed on the image pickup planeof the image pickup device 53 b before photographing.

FIG. 26 illustrates a processing procedure in the present embodimentwhen a picked up image is displayed on the display section 55 throughthe control by the image processing & control section 54 when thesemi-underwater photographing mode is set. When the display switchingprocessing starts, the image processing & control section 54 determineswhether or not the semi-underwater photographing mode is set in firststep S41 a.

When the determination result shows that the semi-underwaterphotographing mode is set, the image conversion section 54 a performsimage processing of reducing the size of the picked up image as shown instep S41 b, and reduces the size to, for example, ½. Furthermore, innext step S41 c, the display control section 54 b displays thecompressed image on the upper half portion of the screen of the displaysection 55 and ends this processing.

On the other hand, when the determination result in step S41 a showsthat the semi-underwater photographing mode is not set, the imageprocessing & control section 54 performs normal image processing asshown in step S41 d. In this case, the image processing & controlsection 54 generates an image for normal display without reducing thesize of the picked up image.

Furthermore, in next step S41 e, the image processing & control section54 performs control so as to perform a normal image display. In thiscase, the display image is displayed using the full screen of thedisplay section 55. After the processing in step S41 e, the processingin FIG. 26 ends.

Since the processing in FIG. 26 is actually processing in step S122 inFIG. 30, when the processing in FIG. 26 ends, the process moves toprocessing in next step S123 in FIG. 30.

When the semi-underwater photographing mode is set, by reducing the sizeof the image and performing display control of the reduced image in thisway, the image is displayed so that the user 63 can simultaneouslyobserve the objects above water and under water as shown in FIG. 25A orFIG. 25B.

Although a case has been described above where when the picked up imageis reduced in size, the image conversion section 54 a reduces the sizethereof to ½, the present invention is not limited to this case, but theuser 63 may set the size of reduction or select a predetermined size ofreduction and allow the selected size to be set. Furthermore, the usermay be allowed to select a case where both sizes in longitudinal andlateral directions are reduced or a case where only the size in thelongitudinal direction is reduced.

Furthermore, when the display position is changed by the display controlsection 54 b, the display position may be enabled to be changed inconjunction with the size of reduction.

Furthermore, when the semi-underwater photographing mode is set, thepresent embodiment is designed to be able to pick up and photographimages of objects above water and under water more clearly.

When the user 63 performs focusing in the semi-underwater photographingmode, the operation above water is easier than that under water. To bemore specific, there are various kinds of inconvenience, for example,since the user 63 cannot breathe under water, the user cannot holdhis/her breath until focusing is done and photographing is performed orit is difficult to perform stable focusing or the like due to buoyancyor the focus position is not stable because fish are actively moving. Bycontrast, no such inconvenience exists above water and the operation iseasier.

FIG. 27 shows a state in which the photographing lens 53 a of the imagepickup section 53 is focused, for example, on an object on the abovewater side when the semi-underwater photographing mode is set for theobject.

The photographing lens 53 a making up the image pickup section 53illustrated in FIG. 27 is allowed to move in the optical axis directionby the drive section 53 e making up the focusing section 53 d.Furthermore, the focusing section 53 d is provided with a positionsensor 53 f, which detects the position of the photographing lens 53 aset by the drive section 53 e and outputs the position information tothe focusing control section 54 c and the distance conversion section 54d of the image processing & control section 54.

As shown in FIG. 27, when focus is achieved, for example, on the figureobject T an object on the above water side, focus is achieved on a(distance) position behind the figure object T under water due to therefractive index under water.

This case (state in which focus is achieved on a position behind thefigure object T under water) is inconvenient because in this direction,focus on fish or the like in front of the figure object T is less likelyto be achieved. Furthermore, for reasons related to underwatertransparency (transmissivity), a distant view is more likely to becomeobscure under water than above water. It is inconvenient to achievefocus on a distant object on the underwater side rather than the abovewater side for this reason, too.

Thus, in the present embodiment, the focusing control section 54 c ofthe image processing & control section 54 performs control such thatfocus is achieved (focus setting) at a shorter distance than the focusposition shown in FIG. 27.

FIG. 28A and FIG. 28B illustrate a control state of the (photographinglens 53 a of the) image pickup section 53 in which this focusing controlsection 54 e has achieved focus. As shown in FIG. 28A, the photographinglens 53 a is set at a position ahead of the position of thephotographing lens 53 a shown in FIG. 27 (position shown by a dottedline in FIG. 28A).

By so setting, focus is achieved at a shorter distance than the focusposition in FIG. 27. FIG. 28A and FIG. 28B illustrate an approximateamount of blur U as the amount of deviation of the image formed on theimage pickup device 53 b through the optical path on the above waterside from the image focused on the underwater side from a position abovewater.

FIG. 28B further illustrates astute in which the brightness (aperture)is narrowed down by a (brightness) diaphragm 53 g provided for the imagepickup section 53 in the state of FIG. 28A. When the diaphragm 53 gnarrows down the brightness, it is possible to increase the depth offield and decrease the amount of blur U compared to the case in FIG.28A.

The focusing processing method here is as shown in FIG. 29. When thefocusing in the semi-underwater photographing mode starts, the focusingcontrol section 54 c of the image processing & control section 54 drivesthe drive section 53 e of the focusing section 53 d in first step S111and moves the photographing lens 53 a in the optical axis direction.

During the movement, the image processing & control section 54 detects acontrast signal corresponding to a difference between the brightnesssignal of the brightest portion and the brightness signal of the darkestportion obtained from each frame if the image pickup signal of the imagepickup device 53 b.

In step S112, the image processing & control section 54 sets thephotographing lens 53 a at a position where the contrast signal reachesa peak. The set position is detected by the position sensor 53 f and theposition sensor 53 f sends the position information to the distanceconversion section 54 d.

In next step S113, the distance conversion section 54 d calculates adistance (referred to as “object distance”) L to the focused object fromthe position information.

Furthermore, in next step S114, the distance conversion section 54 dcalculates a distance on the shorter distance side than the obtainedobject distance L as a focusing distance Lh corresponding to the actualfocusing in consideration of the refractive index of water nw (=1.33)(step S115 will be described later).

In this case, the distance conversion section 54 d of the imageprocessing & control section 54 determines the focusing distance Lh fromL/C using a correction coefficient C (e.g., C=1.3 as a default value aswill be described in FIG. 30) provided beforehand for the objectdistance L.

In other words, the distance conversion section 54 d converts the objectdistance L obtained on the above water side to the focusing distance Lhappropriate for (image pickup and) photographing for both objects abovewater and under water clearly.

The distance conversion section 54 d then sends the focusing distance Lhto the focusing control section 54 e and ends the processing ofcalculating the focusing distance Lh in FIG. 29. In FIG. 30, as will bedescribed later, the processing in step S115 is performed which takesinto consideration the transparency as shown by a dotted line betweensteps S113 and S114 in FIG. 29.

The processing procedure except step S115 in FIG. 29 corresponds to acase where the object on the above water side is at least not distant(e.g., the figure object T) in FIG. 28A and FIG. 28B. In the case of theobject distance L which is farther than the boundary distance Lb whichtakes the underwater transparency into consideration, focus is achievedon the object on the underwater side.

As described above, due to underwater transparency, the object on theunderwater side becomes obscure compared to the object on the abovewater side as the distance increases (the object becomes far) underwater. Therefore, when the object distance L exceeds a predeterminedboundary distance Lb (3 m according to the default value in FIG. 30),the present embodiment gives priority to focusing on the object underwater in consideration of the influence of underwater transparency.

Thus, it is determined in step S115 in FIG. 29 whether or not the objectdistance L is smaller than the boundary distance Lb in consideration oftransparency.

When the object distance L is smaller than the boundary distance Lb, theprocess moves to step S14. On the other hand, when the object distance Lis equal to or greater than the boundary distance Lb focusing isperformed on the object portion under water, as will be described instep S129 in FIG. 30.

Therefore, when performing focusing in the semi-underwater photographingmode, the focusing control section 54 c in the present embodimentcalculates the object distance L with respect to the above water objectand performs control so as to set a focus position by performingfocusing in consideration of the refractive index under water andperforms control, when the object distance L is equal to or greater thanthe boundary distance Lb of transparency, so as to perform focusing onthe object under water.

In other words, the focusing control sec ion 54 c of the presentembodiment performs control so as to set the photographing lens 53 aunder a distance condition in consideration of underwater transparencyand at a focus position at a distance in consideration of the refractiveindex under water.

The operation according to a typical processing procedure associatedwith photographing under the control of the image processing & controlsection 54 in the camera 51 in such a configuration is as shown in FIG.30.

When the photographing operation starts, the image processing & controlsection 54 determines whether or not the user 63 has set a photographingmode in first step S121. When the photographing mode is set, the user 63performs display switching appropriate for the photographing mode innext step S122.

In next step S123, the image processing & control section 54 determineswhether or not the semi-underwater photographing mode is set by the user63. When the semi-underwater photographing, mode is not set, thefocusing control section 54 c of the image processing & control section54 performs focusing in the center of the screen as shown in step S124.After that, the process moves to processing in step S130.

On the other hand, when the semi-underwater photographing mode is net bythe user 63 in step S123, the focusing control section 54 c of the imageprocessing & control section 54 performs focusing in the upper portionof the screen in next step S125 and determines exposure in the lowerportion of the section.

The image processing & control section 54 performs processing such asfocusing on the image on the image pickup plane of the image pickupdevice 53 b (e.g., an image of the object is formed upside down on theimage pickup plane). This will be described with reference to the statein which the object image is displayed on the screen of the displaysection 55 (the object is not turned upside down).

That is, the focusing control section 54 c performs focusing on theobject above water based on the image pickup signal and calculates(detects) the aforementioned object distance L. On the other hand, withregard to the exposure, the focusing control section 54 c determinesexposure so as to obtain brightness appropriate for photographing of theobject on the underwater side.

Furthermore, the present embodiment performs control processing ofsetting the focusing distance Lb in order to be able to also take aclear photograph of the object under water as described above.

In next step S126, the distance conversion section 54 d of the imageprocessing & control section 54 performs (starts) conversion processingon the object distance L.

In next step S127, the distance conversion section 54 d determineswhether or not the object distance L is smaller than 3 m (as a defaultvalue of the boundary distance Lb). When the object distance L issmaller than 3 m, the distance conversion section 54 d sets the focusingdistance described in FIG. 9 to, for example, L/1.3 in step S128. Here,1.3 is a default value of the correction coefficient C.

After that, the focusing control section 54 c sets the photographinglens 53 a at a position corresponding to the focusing distance Lh viathe drive section 53 e. The process then moves to the processing in stepS130. The photographing state of the image pickup section 53 set throughthe processing in step S128 corresponds to the state shown in FIG. 28A(or FIG. 28B).

In step S128 in FIG. 30, the focusing distance Lh is set to L/1.3 sothat the body (human body) portion which is the portion under water ofthe figure object T is set to the focus position.

Such a setting is based on the consideration that the focus balancebetween fish in front of the body portion under water and the bodyportion above water becomes better (focuses on both objects are balancedpreventing such focusing that would cause the image of any one of theobjects to become obscure).

In the above described case, C=1.3 is set as the correction coefficientC, but when the body portion above water and the body portion below thewater surface are assumed to be main photographing objects instead ofassuming the fish under water as main photographing objects, thefocusing distance Lh may be set to on the order of L/1.2.

Thus, for example, C=1.3 may be set as the default value of thecorrection coefficient C and the value of the correction coefficient Cmay be made changeable within a range of, for example, on the order of1.1 to 1.3 through a selection operation by the user 63.

Furthermore, the object under water may turn darker (because oftransparency compared to the above water side), may have lower contrastor may be susceptible to influences of suspended solids or the like, andtherefore in step S125, focusing is performed on the object above waterhaving higher reliability, making it possible to calculate the objectdistance L which has higher reliability (accuracy).

Furthermore, in photographing of such a scene, assuming that there is anobject to be photographed under water, control is performed so as todetermine exposure based on the brightness of the object on theunderwater side. Furthermore, the region may be divided into under waterand above water portions, and when the image processing control section54 performs image processing on images of the respective regions, theamplification factors corresponding to the brightness levels may beswitched so that both regions have appropriate brightness.

On the other hand, when the object distance L is greater than 3 m in thedetermining processing in step S127, the process moves to the processingin step S129. The focusing control section 54 c in step S129 performsfocusing in the lower portion of the screen.

In this case, the object above water is considered to be a distantobject such as landscape, and therefore the image of the object on theunderwater side at such a distant place becomes obscure due tounderwater transparency compared to the above water side or it may bedifficult to pick up an image of the object.

Thus, in the case of the object distance L exceeding the boundarydistance Lb, the focusing control section 54 c of the present embodimentperforms control so as to focus on the object on the underwater side andsets the photographing lens 53 a at the focus position.

In a photographing (image pickup) situation which the image of theobject on the underwater side is likely to become obscure under theinfluence of underwater transparency because the object distance Lexceeds the boundary distance Lb, such a situation is alleviated byfocusing on underwater objects.

In step S130 after step S128 or S129, the image processing & controlsection 54 determines whether or not a release operation is performed.When the release operation is not performed, the process returns to theprocessing in step S121.

On the other hand, when the release operation is performed, the imageprocessing & control section 54 determines in next step S131 whether ornot the semi-underwater photographing mode is set. When thesemi-underwater photographing mode is set, the image processing &control section 54 performs the diaphragm control described in FIG. 28Bin next step S132 and then moves to the processing in step S133.

Furthermore, the image processing & control section 54 also moves tostep S133 when the semi-underwater photographing mode is not set. Instep S133, the image processing & control section 54 performsphotographing in the focusing state in step S128 or S129 and alsorecords the photographed image in the recording section 58. In thiscase, the date and time information in the clock section 59 is alsorecorded in association with the recorded image in the recording section58.

On the other hand, when the photographing mode is not set in step S121,the image processing & control section 54 determines in step S134whether or not a reproducing mode is set. When the reproducing mode isnot set, the image processing & control section 54 moves to step S136.

On the other hand, when the reproducing mode is set, the imageprocessing & control section 54 reproduces the image recorded in therecording section 58 in step S135. In next step S136, the imageprocessing & control section 54 determines whether or not an endoperation is performed. When the end operation is not performed, theimage processing & control section 54 returns to the processing in stepS121, and when the end operation is performed, the power of the camera51 is turned OFF and the processing in FIG. 30 ends.

The camera 51 according to the sixth embodiment that performs such anoperation can simultaneously and clearly photograph objects above waterand under water in consideration of influences of the refractive indexand transparency under water through a simple operation. Furthermore,the camera 51 according to the present embodiment does not need anydedicated adapter or the like and can easily photograph objects abovewater and underwater simultaneously and clearly.

Seventh Embodiment

Next, a seventh embodiment, of the present invention will be described.FIG. 31 illustrates a configuration of a camera 51B according to theseventh embodiment of the present invention.

The camera 51B of the present embodiment corresponds to the camera 51 inFIG. 21 further provided with an acceleration detection section 65 as anexample of posture detection means for detecting the posture of thecamera 51B. The acceleration detection section 65 is made up of threeacceleration sensors for detecting acceleration in three axialdirections of the case 52; vertical, horizontal and depth directionsorthogonal to each other.

Signals detected by the three acceleration sensors are inputted to theimage processing & control section 54. The image processing & controlsection 54 has the function of a posture detection section that detectsthe posture (the vertical direction along the perpendicular direction inwhich gravity acts, or the like) in a photographing state includingimage pickup of the camera 51B from signals of the three accelerationsensors.

Furthermore, the present embodiment can perform not only semi-underwaterphotographing in the semi-underwater photographing mode of the sixthembodiment when the water surface does not change so much but alsosemi-underwater photographing in a second semi-underwater photographingmode when the water surface drastically changes with respect to the lensdiameter of the photographing lens 53 a.

Thus, the image processing & control section 54 has a water surfacevariation detection section 54 e as second semi-underwater photographingmode determining means for detecting (determining) whether or not thephotographing state is in a second semi-underwater photographing mode inwhich the water surface fluctuates when the semi-underwaterphotographing mode is set.

Furthermore, as will be described later, the image processing & controlsection 54 of the present embodiment has the function of anidentification section 54 f that identifies, upon detecting the imageportion or the water surface in the image of the object whose image hasbeen picked up using a detection (determination) of the posture in thevertical direction of the camera 51B when the semi-underwaterphotographing mode is set, the image (region) of the object above waterwhich is the upper side thereof and the image (region) of the objectunder water which is the lower side thereof.

Furthermore, the image processing & control section 54 of the presentembodiment has the function of a semi-underwater photographing modedetermining section 54 g that determines whether or not the camera 51Bis set in a photographing state in the semi-underwater photographingmode. The processing procedure of the semi-underwater photographing modedetermining section 54 g is as shown in FIG. 40A and FIG. 43.

The configuration of the front side and the back side of the camera 51Bof the present embodiment are as shown in FIG. 32A and FIG. 32B. Asshown in FIG. 32A, the camera 51B is provided with a photographing lens53 a at a position, for example, on the left top side rather than thecenter position of the front side.

That is, the camera 51B is provided with the photographing lens 53 adecentered leftward in, for example, the longitudinal direction withrespect in the center position of the front side. Including the factthat the case 52 is oblong and the display section 55 is also formed tobe oblong, the rest of the configuration is substantially the same asthat of the camera 51 of the sixth embodiment.

In this case, as shown in FIG. 33, when the user 63 rotates the camera51B from the state shown in FIG. 32A by 90° so that the decenteredphotographing lens 53 a side becomes lower (than the center), submergespart of the camera 51B below the water surface of a pond 71 and performssemi-underwater photographing, the user can perform, photographingthrough a simple operation while checking the image displayed on thescreen of the display section 5.

FIG. 34 illustrates an example of image when photographing is performedby setting the camera 51B in the semi-underwater photographing mode asshown in FIG. 33. As shown in FIG. 34, it is possible to simplyphotograph not only floating grass that straddles above water and underwater in the pond 71 but also fish swimming under water.

FIG. 35A and FIG. 35B illustrate the posture of the camera 51B set bythe user 63 in the case of FIG. 33.

When the user 63 performs semi-underwater photographing using the camera51B with the arrangement shown in FIG. 32A and FIG. 32B checking imagesbut without diving into the water, if the user holds the camera 51B inthe vertical (vertically oblong) direction so that the photographinglens 53 a side comes close to the bottom as shown in FIG. 35A and FIG.35B, it is possible to perform photographing with only substantiallyhalf the size of the photographing lens 53 a submerged in water and muchof the display section 55 exposed above water.

However, only images in vertical composition can be taken in this case,but this way of photographing is preferable when the photographer wantsto photograph objects in deep water. Thus, the present embodiment allowssemi-underwater photographing to be simply performed.

In this case, much of the screen made up of the liquid crystal panelthat constitutes the display section 55 can be used, and it is therebypossible to determine a screen usable region (abbreviated as “usableregion”) 55 a used for image display and a non-use region 55 b not usedfor image display (as partial screen region in the lower portion) withreference to the center position of the photographing lens 53 a (seeFIG. 35B).

Furthermore, the image conversion section 54 a performs image processingthat slightly reduces the size of a picked up image, for example, in thelongitudinal direction so as to be displayed on the use region 55 a.

Furthermore, a water surface guideline such as a line 55 c indicating awater surface guideline is displayed when a semi-underwaterphotographing mode is set so that it is recognizable from the displayscreen of the display section 55 on the hack side of the camera 51B thatthe camera 51B in the state shown in FIG. 35B is submerged in water fromthe bottom thereof and set in a state appropriate for semi-underwaterphotographing, that is, a reference position in which the centerposition of the photographing lens 53 a matches the water surface.

In addition to displaying the line 55 c indicating the water surfaceguideline on the screen of the display section 55 or the like, a marksuch as a line indicating the water surface guideline may also beprovided on the back side of the case next to the line 55 c (referencenumeral 55 d shown by a dotted line in FIG. 35B).

In this case, display switching of an image is performed according to aflowchart shown, for example, in FIG. 36. When the display switchingoperation starts, the image processing & control section 54 determinesin first step S141 whether or not the semi-underwater photographing modeis set according to a detection signal by the acceleration sensor of theacceleration detection section 65.

According to the present embodiment, when the user 63 changes the camera51B from the photographing state in FIG. 32A to the longitudinalcomposition shown in FIG. 35A, the image processing & control section 54determines that the semi-underwater photographing mode is set. Adetermination may also be made on the setting operation by the user 63using the semi-underwater photographing mode button 56 c as in the caseof the sixth embodiment.

Furthermore, whether or not the semi-underwater photographing mode isset may also be determined through semi-underwater photographing modedetermining processing in FIG. 40A, which will be described later.

When the semi-underwater photographing mode is set, as shown in stepS142, the image conversion section 54 a performs image processing thatslightly reduces the size of a picked up image, for example, in thelongitudinal direction so as to be displayed on the use region 55 a.

Furthermore, in next step S143, the display control section 54 bdisplays alive view of the image slightly reduced in the longitudinaldirection in the use region 55 a of the display section 55.

Furthermore, in next step S144, the image processing & control section54 performs a mode display indicating that the under water photographingmode is set, a direction display indicating that image pickup(photographing) is performed in vertically longitudinal composition, ina portrait mode, a display of a water surface guideline positionindicating a water surface guideline, and ends the processing in FIG.36.

On the other hand, when the determination result in step S141 shows thatthe semi-underwater photographing mode is not set, the image processing& control section 54 performs normal image processing as shown in stepS145. In this case, the image processing & control section 54 generatesan image for normal display from the picked up image.

Furthermore, in next step S146, the image processing & control section54 performs display control over the normal image, in this case, thenormal image is displayed using the entire display region of the displaysection 55. After this processing, the processing in FIG. 36 ends.

Since the camera operates in this way, when the semi-underwaterphotographing mode is set, a picked up image is displayed only in theuse region 55 a within the screen of the display section 55, the user 63can easily set the photographing lens 53 a at a position appropriate forthe semi-underwater photographing mode according to the display of thewater surface guideline position and secure excellent operability(convenience). Therefore, the user 63 can readily submerge part of thecamera 51B in water and enjoy semi-underwater photographing.Furthermore, in this case, the size of the use region 55 a can beincreased compared to the sixth embodiment.

Next, the present embodiment will be described with a case wherephotographing is performed in the sea where the water surface fluctuatesdrastically. FIG. 37A and FIG. 37B illustrate a situation in which theuser 63 sets the camera 51B in a semi-underwater photographing mode andtakes a photograph in the sea.

Due to a wave 81 greater than the lens diameter of the photographinglens 53 a, even if the photographing lens 53 a of the camera 51B is setnear the water surface, the photographing lens 53 a deviates from aposition appropriate for semi-underwater photographing as shown in FIG.37A and FIG. 37B.

FIG. 37A illustrates a situation in which the wave 81 forms a troughimmediately before the photographing lens 53 a. In this state, thephotographing lens 53 a is located in air above the wavefront. In thisstate, the portion shown by hatching from the trough to the crest of thewave 81 immediately before the photographing lens 53 a constitutes aregion that obstructs image pickup of an object (to be photographed)(that is, the region where the image is picked up in an out-of-focus,low contrast state, obscurely and photographing of the object issubstantially impossible) 32 a. θ represents a field of view of thephotographing lens 53 a of the camera 51B.

In this case, the image displayed on the display section 55 is as shownin FIG. 38A. Due to the region 82 in FIG. 37A, images of some objects inthe upper-side part of the field of view θ of the camera 51B can bepicked up and displayed, hut an image region 82 b exists therebelowwhere objects to be photographed cannot be photographed due to theregion 82 a.

Furthermore, FIG. 37B illustrates a state in which the camera 51B issubmerged in water into a crest of the wave 81. The area shown byhatching constitutes a region 82 c which obstructs image pickup of theobject to be photographed in this state, too. In this case, the imagedisplayed on the display section 55 is as shown in FIG. 38B.

Although an image of the object corresponding to only part of thelower-side portion of the field of view of the camera 5113 can be pickedup and displayed due to the region 82 c in FIG. 37B, an image region 82d is generated thereabove where the object to be photographed cannot bephotographed due to the region 82 c.

The state of the image displayed on the screen of the display section 55in FIG. 37A and FIG. 37B or FIG. 38A and FIG. 38B is caused by the wave81, and therefore the brightness of the upper and lower portions of thescreen frequently varies with time due to the wave 81.

Thus, it is possible to temporally monitor the variation in brightnessin the upper and lower portions of the screen on which images aredisplayed and thereby detect (determine) this state. In the presentembodiment, the water surface variation detection section 54 e of theimage processing & control section 54 detects this state, for example,according to a flow shown in FIG. 40C.

The relationship between the vertical, horizontal directions of theobject image formed on the image pickup plane of the image pickup device53 b and the vertical, horizontal directions of the image displayed onthe (display) screen of the display section 55 is determined far eachcamera. The processing of monitoring a variation in the brightness inthe upper and lower portions of the screen is equivalent to processingon a picked up image obtained from the object image formed on the imagepickup plane of the image pickup device 53 b.

The present embodiment enables semi-underwater photographing to beperformed in a second semi-underwater photographing mode correspondingto a situation in which the water surface fluctuates drastically inaddition to the semi-underwater photographing mode in a situation wherethe water surface does not fluctuate so much.

Thus, when semi-underwater photographing is performed in the presence ofthe temporally fluctuating wave 81 larger than the lens diameter, thiscan hardly be considered as a situation in which a macro region as shownin FIG. 33 or FIG. 34 is photographed in semi-underwater condition.

When the brightness fluctuates between upper and lower portions of thescreen, the focus is adjusted at a distance of 1 m or more and since thewater underneath the wave 81 is bubbling and the transparency(transmissivity) under water is estimated to be low, the focus need notbe adjusted at a distance of 2 m or more.

By estimating the photographing situation in this way, when the secondsemi-underwater photographing mode is set, the focusing control section54 c of the present embodiment performs focusing control whereby a fixedfocus whose default value is approximately 1.5 no is set as the focusposition after the mode is determined to be the second semi-underwaterphotographing mode producing a photographing situation in which thewater surface fluctuates. On the other hand, after the determinationresult shows that the second semi-underwater photographing mode is set,a focusing distance using a fixed focus (e.g., 1.5 m as a default value)is adopted.

Furthermore, since the brightness of part of the screen quickly varies,the image processing & control section 54 determines exposure based onthe overall brightness.

Moreover, since it is almost impossible to perform photographing at thebest moments, photographing is performed in a continuous shooting(continuous photographing and recording) mode.

The processing procedure when performing photographing according to thepresent embodiment including the aforementioned features of the secondsemi-underwater photographing mode is as shown in FIG. 39.

Since the processing procedure in FIG. 39 is similar to the processingprocedure in FIG. 30, only differences will be described. Step S50 tostep S52 in FIG. 39 are the same procedure as that in step S121 to stepS123 in FIG. 30.

When the photographing mode is not set in step S50, the process moves tostep S64. Step S64 to step S66 is the same processing as that in stepS134 to step S136 in FIG. 30.

In step S51, the processing of display switching shown in FIG. 36 isperformed. Furthermore, whether or not the semi-underwater photographingmode is set in step S52 may be determined using the detection result bythe acceleration sensor of the acceleration detection section 65 or thedetermination in FIG. 40A in addition to the switch operation by theuser 63. Using FIG. 40A improves the operability.

When the determination result in step S52 shows that the semi-underwaterphotographing mode is not set, whether or not the second semi-underwaterphotographing is set is determined in next step S53. When it is detectedthat the brightness varies drastically with time between the upper andlower portions of each frame in a picked up image, the mode isdetermined as the second semi-underwater photographing mode. Thisdetermination is made in step S67 which will be described later.

Thus, it is determined in step S53 that the second semi-underwaterphotographing mode is not set in an operation state close to thebeginning where the processing in FIG. 39 starts. The flow then moves toprocessing of focusing in the center of the screen in step S54. Thisprocessing is the same processing as that in step S124 in FIG. 30.

On the other hand, when it is determined in step S52 that thesemi-underwater photographing mode is set, the process moves toprocessing in step S53. The processing from step S55 to step S63 iscompletely the same as that in step S125 to step S133 in FIG. 30 (exceptstep S130 of release operation determining processing) if the releaseoperation determining processing in step S60 is excluded.

When the release operation is performed in step S60, the imageprocessing & control section 54 moves to step S61, whereas when therelease operation is not performed, the water surface variationdetection section 54 e of the image processing & control section 54performs processing of determining in step S67 whether or not the secondsemi-underwater photographing mode setting condition is met.

The determination result as to whether or not the second semi-underwaterphotographing mode setting condition is met is recorded in a memory (notshown) in the image processing & control section 54 together withinformation on the determined time.

The determination result is used later for the determining processing instep S53. In this case, the result determined to correspond to thesecond semi-underwater photographing mode is stored for a period, forexample, on the order of several times the period of the wave 81 aseffective information. After the determining processing in step S67, theprocess returns to the processing in step S50, and the processing shownin FIG. 39 is repeatedly performed fast.

Therefore, in a situation in which semi-underwater photographing isperformed in the presence of the wave 81 as shown in FIG. 37A or FIG.37B, after the determination corresponding to the second semi-underwaterphotographing mode setting condition is made according to first severaltimes of the fluctuating wave 81, (in step S67 the time of determinationcorresponding to the second semi-underwater photographing mode isupdated through the processing in the loop in FIG. 39), thedetermination result corresponding to the second semi-underwaterphotographing mode is continuously stored.

When it is determined in step S53 that the second semi-underwaterphotographing mode is set, the object distance L is set to 1.5 m, thedefault value of fixed focus in step S68.

Furthermore, the image processing & control section 54 sets exposure onthe full screen. In step S69 after the processing in step S68, the imageprocessing & control section 54 determines whether or not a releaseoperation is performed.

When the release operation is performed, the image processing & controlsection 54 performs continuous photographing in step S70, continuouslyrecords images in the recording section 58, and then returns to theprocessing in step S50. By performing such continuous photographing, itis possible to record a plurality of photographed images taken throughcontinuous shooting in a short time interval even when it is difficultto perform photographing at the best photographing timing, there is ahigh possibility that the user 63 may acquire photographed images ofabove water objects and underwater objects simultaneously taken atexcellent photographing timings among the photographed images.

On the other hand, when the release operation is not performed in stepS69, the process returns to the processing in step S50 after performingimage processing of determining in step S67 whether or not the secondsemi-underwater photographing mode setting condition is met.

FIG. 40A illustrates an example of the processing procedure in step S52in FIG. 39. The image processing & control section 54 has the functionof the semi-underwater photographing mode determining section 54 g shownin FIG. 31 by performing the following processing.

When the semi-underwater photographing mode determining processingstarts, the image processing & control section 54 determines whether ornot there is a variation in contrast in the center of the screen infirst step S71. In this case, the image processing & control section 54identifies (determines) the vertical direction of the camera 51B fromthe direction of gravity acceleration using the acceleration sensor. Itis then determined whether or not there is a contrast variation near thecenter of the screen in the vertical direction.

When there is a boundary (water surface) of water in the center of thescreen, there is a variation in contrast between the underwater sidethat absorbs light and the above water side that less absorbs lightacross the water surface as the boundary.

Upon determining that there is a contrast variation in the center of thescreen, the image processing & control section 54 determines in nextstep S72 whether or not the boundary of the contrast variation crossesthe screen. In the case of the water surface, the boundary of thecontrast variation crosses the screen.

When the determination result shows that the boundary of the contrastvariation crosses the screen, the image processing & control section 54performs processing of comparing contrast between the upper and lowerportions of the screen in next step S73. The image processing & controlsection 54 determines (identifies) (the posture of) the upper and lowerportions of the screen from the signal of the acceleration sensor inthis case, too.

In next step S74, the image processing & control section 54 determineswhether or not the lower portion of the low contrast region of the watersurface portion having low contrast is dark. It is also possible tosimply determine whether or not the image in the lower portion is darkerthan the image in the upper portion. In the case of the object as shownin FIG. 40B, the underwater side in the lower portion is darker.

When the determination result shows that the lower portion is darker,the image processing & control section 54 compares the color tonebetween the upper and lower portions of the screen in next step S75. Theimage processing & control section 54 determines in next step S76whether or not the red component in the lower portion is smaller thanthat in the upper portion.

When the red component in the lower portion is smaller than that in theupper portion, the image processing & control section 54 determines instep S77 that the photographing state is in the semi-underwaterphotographing mode. The image processing & control section 54 then movesto processing in step S55 in FIG. 39.

On the other hand, when the determination results in steps S71, S72, S74and S76 are negative, the image processing & control section 54determines in step S78 that the photographing state is not in thesemi-underwater photographing mode and moves to processing in step S53in FIG. 39.

A determination may also be made in step S77 or S78 based on thedetermination result of one of determining processing in two steps S74and S76.

From the determination result in step S77, it is possible to assume theportion where the boundary of the contrast variation crosses the screenin the center of the screen in step S72 to be the water surface anddetermine (identify) that the upper portion thereof is the object abovewater and the lower portion thereof is the object under water.

FIG. 40B is a diagram illustrating the determination of thesemi-underwater photographing mode in FIG. 40A and FIG. 408 illustratesa typical example of the object in the photographing state in thesemi-underwater photographing mode.

As shown in FIG. 40B, the region under water has lower transparency, andis darker due to absorption of light, often includes suspended solidsthan the region above water, and thus constitutes a low contrast regionhaving low contrast for these reasons.

Furthermore, the wavelength of red light on the long wavelength side inthe visible region in particular is more easily absorbed than the shortwavelength side and is more likely to have blue color tone (in otherwords, color tone with less red component). Therefore, the processingprocedure in FIG. 40A can be used to determine the semi-underwaterphotographing mode.

Furthermore, the second semi-underwater photographing mode in step S53in FIG. 39 is determined using the processing procedure shown in FIG.40C.

When the second semi-underwater photographing mode determiningprocessing starts, the image processing & control section 54 determinesin first step S81 whether or not there is any posture variation of thecamera 51B according to a signal from the acceleration sensor.

That is, when semi-underwater photographing is performed, the user 63keeps the posture of the camera 51B (optical axis direction of thephotographing lens) in the horizontal direction or a posture close tothis as shown in FIG. 37A. The image processing & control section 54then determines whether or not there is any acceleration variation inthe optical axis direction of the photographing lens.

When the determination result shows that there is no variation in theposture of the camera 51B, the image processing & control section 54determines in next step S82 whether or not there is a large timevariation in the image in the screen. When the determination resultshows that there is a large time variation in the image in the screen,the image processing & control section 54 compares contrast between theupper and lower portions of the screen in next step S83.

In next step S84, the image processing & control section 54 determineswhether or not the lower portion is darker. When the determinationresult in step S84 shows that the lower portion is darker, the imageprocessing & control section 54 further compares the color tone betweenthe upper and lower portions in next step S85.

In next step S86, the image processing & control section 54 determineswhether or not the red component in the lower portion is smaller (thanthat in the upper portion).

When the determination result shows that the red component in the lowerportion is smaller than that in the upper portion, the image processing& control section 54 determines in step S87 that the photographing stateis in the second semi-underwater photographing mode. The imageprocessing & control section 54 then moves to processing in step S68 inFIG. 39.

On the other hand, when the determination results in the determiningprocessing in steps S81, S82, S84 and S86 are negative, the imageprocessing & control section 54 determines in step S88 that thephotographing state is not in the second semi-underwater photographingmode. The image processing & control section 54 then moves to processingin step S54 in FIG. 39. The determination in step S87 or S88 may also bemade based on the determination result of one of the determiningprocessing in two steps of S84 and S86.

The present embodiment that performs such an operation not only has theeffects of the sixth embodiment but also performs continuous shootingwhen the water surface fluctuates drastically, and can thereby acquirephotographed images photographed at excellent photographing timings.

The seventh embodiment is also applicable to a cellular phone with awaterproof camera provided with a waterproof function as shown in FIG.41 (hereinafter referred to as “cellular phone”) 90, FIG. 41 illustratesan operation example in which the user 63 is observing objects abovewater and objects under water in a pond 92 in a semi-underwaterphotographing mode setting state using the cellular phone 90.

The cellular phone 90 is made up of a camera section 91 provided with animage pickup section 53 that picks up an image and a display section 95that performs display, which are independent bodies but foldablyconnected together by a folding section. The camera in the modificationexample is formed of the camera section 91 and the display section 95.Although the present embodiment will be described taking the cellularphone 90 as an example here, the present embodiment is also applicableto a camera in a foldable configuration such as the camera section 91(or image pickup section 53) and the display section 95.

Therefore, the user 63 sets the camera section 91 and the displaysection 95 in a state with an angle of for example, on the order of 60°,submerges the vicinity of the center of the photographing lens of thecamera section 91 in water up to a water surface 92 a of the pond 92 asshown in FIG. 41, and can thereby realize a setting state in asemi-underwater photographing mode. The user 63 can thereby readilyenjoy the image picked up in that setting state from the image displayedon the display section 95.

In the case of FIG. 41, due to fluctuations of the water surface 92 a inthe pond 92, which are not so big as in the case of sea, the regioncorresponding to fluctuations of the water surface 92 a within a fieldof view θ of the photographing lens (region shown by hatching) 92 bconstitutes a region where image pickup is actually almost impossible.

In this case, the image displayed on the display section 95 is as shownin FIG. 42 and there is an image region 95 a of the region 92 b due tofluctuations of the water surface 92 a shown by hatching in FIG. 41.

The image region 95 a becomes a region (low contrast region) which isout of focus has low contrast and extends in a band shape in thehorizontal direction.

Therefore, it is possible to determine the water surface section as thewater surface 92 a portion accompanied by fluctuations by detecting theimage region 95 a from the image acquired by the camera section 91 as alow contrast region without the need to display the water surfaceguideline position described in FIG. 35B.

Furthermore, it is also possible to determine the water surface section,take the relationship between the camera section 91 and the displaysection 95 into consideration or detect gravity acceleration using anacceleration sensor, determine the longitudinal direction of the camerasection 91 at the time of image pickup and determine or identify theabove, water side (object above water) and underwater side (object underwater). The identification section 54 f shown in FIG. 31 performs suchidentification.

It is possible to automatically perform focusing control or exposurecontrol according to the identification result and save the user 63 timeand trouble in performing an instruction operation.

By identifying objects above water and under water in this way, thepresent embodiment can improve operability in addition to the operationsand effects of the sixth embodiment. Furthermore, by adding theacceleration detection section 65 to the sixth embodiment, it islikewise possible to improve operations and effects thereof. Theidentification section 54 f can determine contents described, forexample, as the upper portion of the screen and the lower portion of thescreen in step S125 in FIG. 30 and step S55 in FIG. 39 as an objectabove water and an object under water respectively.

Furthermore, semi-underwater photographing with excellent operability ispossible. According to the aforementioned photographing processingprocedure in FIG. 39, when the determination result shows that thesemi-underwater photographing mode is not set, a determination is madeon whether or not the second semi-underwater photographing mode is set,but the semi-underwater photographing mode and the secondsemi-underwater photographing mode may be determined comprehensively aswill be described in the following modification example.

FIG. 43 includes the processing procedure associated with theidentification section 54 f shown in FIG. 31. Furthermore, FIG. 43 alsoillustrates a processing procedure for automatically determining whetherthe photographing state is in the semi-underwater photographing mode orsecond semi-underwater photographing mode from the image acquired by theimage pickup section 53 when the photographing mode is set.

In first step S91, the identification section 54 f of the imageprocessing & control section 54 determines whether or not a low contrastregion R1 exists in the center of the screen in an image picked up bythe image pickup section 53 (when displayed as the center of each frameor image).

The identification section 54 f detects a pixel region whose contrast isequal to or below a predetermined threshold from a contrast signal of apicked up image and determines the pixel region equal to or below thethreshold as the low contrast region R1.

When the determination result shows that the low contrast region R1exists, the identification section 54 f determines in next step S92whether or not the low contrast region R1 crosses the screen thehorizontal direction). In this case, the identification section 54 f candetermine a horizontal direction (perpendicular to the verticaldirection of the screen determined through gravity acceleration from asignal of the acceleration sensor).

When the determination result shows that the low contrast region R1crosses the screen, the identification section 54 f determines thevertical direction of the screen from the signal of the accelerationsensor in next step S93.

Based on the determination result, (the image of) the upper portion ofthe screen is determined to be (the image region of) of the object abovewater in air and the lower portion of the screen is determined to be(the image region of) the object under water in step S94 and in stepS95.

Using the low contrast region R1 corresponding to the presence of thewater surface and information on the posture of the camera SIB from theacceleration sensor at the time of image pickup, the identificationsection 54 f identifies the image region of an object above water andthe image region of an object under water in the picked up image.

In next step S96, the identification section 54 f determines whether ornot the low contrast region R1 extends to the top end or the bottom end.When the determination result shows that the low contrast region R1extends to the top end or the bottom end, the identification section 54f determines that the second semi-underwater photographing mode is setin which there is a large variation of the wavefront and ends theprocessing in FIG. 43.

On the other hand, when the determination result of determiningprocessing in step S91 shows that no low contrast region R1 exists inthe center of the screen, the identification section 54 f determines instep S98 that the semi-underwater photographing mode is not set and endsthe processing in FIG. 43.

Furthermore, when the determination result of determining processing instep S96 shows that the low contrast region R1 does not extend to thetop end or the bottom end (e.g., the image as shown in FIG. 42), theidentification section 54 f determines that the semi-underwaterphotographing mode is set.

By performing such control using the identification result of theidentification section 54 f the user 63 need not perform an instructionoperation on the camera 51B so as to set the semi-underwaterphotographing mode or the second semi-underwater photographing mode.

The user 63 sets the camera 51B as shown in FIG. 33, FIG. 37A (or FIG.37B), the camera 51B thereby automatically determines that thesemi-underwater photographing mode or the second semi-underwaterphotographing mode is set and performs the corresponding controloperation such as focusing and exposure control.

Therefore, the camera 51B of the seventh embodiment improves theoperability compared to the sixth embodiment, and can readily photographobjects above water and objects under water in the semi-underwaterphotographing mode simultaneously and clearly. Furthermore, even in thesecond semi-underwater photographing mode, the present embodimentprovides a higher possibility that objects above water and objects underwater may be photographed simultaneously.

Furthermore, after determining that the photographing state is in thesemi-underwater photographing mode or second semi-underwaterphotographing mode described in FIG. 43, it is possible to performphotographing on an image of an object above water and an image of anobject under water according to the identification result by theidentification section 54 f by a processing procedure shown in FIG. 44.The processing procedure in FIG. 44 is included in the detailedprocessing procedure shown in FIG. 39 or the like, but further includespartially different contents.

In step S101, the image processing & control section 54 automaticallydetermines (e.g., in the processing procedure in step S123) that thephotographing state is in the semi-underwater photographing mode or thesecond semi-underwater photographing mode.

In next step S102, the identification section 54 f determines(identifies) (the image region of) an object above water and (the imageregion of) an object under water of a photographed image as describedabove.

Furthermore, in next step S103, the image processing & control section54 performs a control operation of focusing and exposure control(exposure determination) corresponding to objects above water andobjects under water according to the above described two photographingmodes.

In this case, the user 63 may make a presetting so as to perform,different image processing on each image (region) of objects above waterand objects under water and the image processing & control section 54may perform different image processing on the respective imagesaccording to the setting.

For example, in step S104, the image processing & control section 54performs image processing on images of all or one of objects above waterand objects under water according to the setting by the user 63. Forexample, the image processing & control section 54 can performprocessing of enhancing a red color or enhancing contours on images ofobjects under water.

Through the processing of enhancing a red color, it is possible togenerate an image with variations in color tone between the above waterside and the underwater side suppressed.

The display section 55 then displays the image subjected to imageprocessing and ends the processing in FIG. 44. Thus, the presentembodiment improves operability, and can more flexibly meet preferencesor the like of the user 63 and widely satisfy different needs.

Based on the identification result by the identification section 54 f,the brightness may be appropriately set for images of each region of theobject above water side and the object under water side for example, bychanging amplification factors when the image processing & controlsection 54 performs image processing. That is, the object under waterside tends to have a darker image than the object above water side, andtherefore greater amplification factors may be set for the images of theobjects under water than the images of the objects above water so thatthe brightness of both images may be controlled to appropriatebrightness. In this case, images of both the objects above water and theobjects under water gin be made easier to see.

Furthermore, an embodiment configured by partially combining theaforementioned embodiments or the like also belongs to the presentinvention. Furthermore, the flowchart of each embodiment or the likeillustrates an example of a typical processing procedure, but theflowcharts are not limited to such specific examples.

Eighth Embodiment

A camera 51C having a waterproof structure provided with a photographingfunction of an eighth embodiment of the present invention shown in FIG.45 has a box shape as shown in FIG. 46A and FIG. 46B. A photographinglens 53 a that constitutes an image pickup section 53 for picking up(photographing) an image of an object is provided at a position on theleft side from the center and closer to the top of the front side of acase 52 having a waterproof structure as an enclosure of this camera51C.

Actually, as shown in FIG. 48, FIG. 49 and FIG. 50, a cover glass 53 cis disposed in front of a photographing lens 53 a, which makeswatertight and protects the photographing lens 53 a. Furthermore, thecover glass 53 c and the photographing lens 53 a are mounted in a lensbarrel (not shown). An image pickup device 53 b such as charge-coupleddevice (CCD) is disposed at an image forming position of thephotographing lens 53 a and the photographing lens 53 a and the imagepickup device 53 b form an image pickup section 53 in FIG. 45.

Furthermore, as shown in FIG. 45, the image pickup section 53 canachieve focus of an object image formed on the image pickup plane of theimage pickup device 53 b through the focusing section 53 d. The focusingsection 53 d is configured using, for example, a drive section 53 e (seeFIG. 48) that moves the photographing lens 53 a in the optical axisdirection.

Instead of moving the photographing lens 53 a by the drive section 53 e,the image pickup device 53 b may be configured to move in the opticalaxis direction. Furthermore, although the image pickup section 53 andthe focusing section 53 d are shown in FIG. 45 or the like asindependent bodies, the image pickup section 53 may be configured toinclude the focusing section 53 d.

The image pickup device 53 b of the image pickup section 53 outputs animage pickup signal (image data), which is an object image formed on theimage pickup plane and then photoelectrically converted, to an imageprocessing & control section 54 that performs image processing andcontrol shown in FIG. 45.

The image processing & control section 54 performs image processing onthe image pickup signal, generates an image signal for display andoutputs the image signal to a display section 55. The display section 55displays an image corresponding to the inputted image signal for displayon a display screen also simply referred to as a “screen”).

The image displayed on the display section 55 is an image correspondingto the object image formed on the image pickup plane of the image pickupdevice 53 b and the user observes the image and thereby checks whetheror not record the image as a photographed image.

Thus, in the normal photographing mode, the image processing & controlsection 54 displays the object image formed on the image pickup plane ofthe image pickup device 53 b on the screen of the display section 55 asa normal image.

The display section 55 is formed on the back side of the case 52 asshown in FIG. 46B using, for example, a liquid crystal panel in arectangular size which is slightly smaller than the whole back sideplane.

Furthermore, as shown in FIG. 46A and FIG. 46B, a release button 56 athat performs a photographing operation is provided on, for example, theright side of the top surface of the case 52. When the photographer(user) operates an operation section 56 including the release button 56a as shown in FIG. 45, the operation result is determined by anoperation determining section 57.

The information on the determination result of the operation determiningsection 57 is inputted to the image processing & control section 54. Theimage processing & control section 54 performs control corresponding tothe determination result.

When the operation determining section 57 determines a release operation(photographing instruction operation), the image processing & controlsection 54 records the image picked up by the image pickup section 53 ina recording section 58 as a photographed image.

Furthermore, a mode setting switch 56 b as shown in FIG. 46B is providedas the operation section 56 shown in FIG. 45.

Operating the mode setting switch 56 b, the user can set a photographingmode or a reproducing mode, set a semi-underwater photographing modewhich will be described later, perform setting for focusing or the likefrom a switch menu.

The mode setting switch 56 b has the function of a semi-underwaterphotographing mode setting section for setting a semi-underwaterphotographing mode.

In addition to the mode setting switch 56 b that has a plurality ofsetting functions, operation buttons or the like may be provided wherebythe user directly performs various instruction operations. Furthermore,operation buttons may be provided which independently perform aplurality of functions that can be selected from the mode setting switch56 b.

For example, FIG. 45 shows an example where a semi-underwaterphotographing mode button 56 c is provided as an independent body in theoperation section 56 as the semi-underwater photographing mode settingsection for setting the semi-underwater photographing mode. According tothe present embodiment, the image processing & control section 54 isprovided with the function of a semi-underwater photographing modedetermining section 54 g that automatically recognizes a photographingstate in a semi-underwater photographing mode as will be describedlater. Thus, the user need not manually operate the semi-underwaterphotographing mode button 56 c in a state in which automatic recognitionis set to be performed.

Furthermore, the present embodiment performs focusing (focus balance)control over the image of the object on the above water side (objectabove water) when the semi-underwater photographing mode is set, butwhen the distance to the object on the above water side is large (forexample, when the distance exceeds a boundary distance Lb set accordingto transparency), the present embodiment provides a condition whichgives priority to focusing on the image of the object on the underwaterside (object under water) in consideration of underwater transparency.

The boundary distance Lb is set to, for example Lb=3 m as a defaultsetting. The user can change/set the boundary distance Lb to a valuecorresponding to the actual underwater transparency by operating aboundary distance setting button (not shown).

A clock section 59 that outputs information on a clock is connected tothe image processing & control section 54 and when a photographingoperation or the like is performed, the image processing & controlsection 54 adds information on a photographing date and time to theimage recorded in the recording section 58 and records theinfo/illation. Furthermore, a strobe apparatus 60 is provided on thefront of the case 52 as shown in FIG. 46A.

An acceleration detection section 65 as a posture detection section thatdetects the posture of the camera 51C at the time of photographing inparticular is connected to the image processing & control section 54.The acceleration detection section 65 is made up of three accelerationsensors accommodated in the case 52 for detecting acceleration acting invertical, horizontal and depth directions of the case 52 respectively.

FIG. 57B illustrates a state in which the long sides of the case 52 arevertically oriented and parallel to the vertical direction in whichgravity acts so that the image pickup section 53 of the camera 51C islocated closer to the bottom, which is appropriate for semi-underwaterphotographing. In this case, an acceleration sensor 65 a shown by adotted line that detects gravity (acceleration) that acts in thelongitudinal direction detects that the longitudinal direction is theposture corresponds to the vertical direction of the image.

The camera 51C of the present embodiment has as one of its objects to beable to photograph objects above water such as the face of a figure onthe above water (above the water surface) side, ship and landscape andobjects under water such as part of the figure on the underwater (belowthe water surface) side, fish, turtle, water plant as shown in FIG. 47Asimultaneously (that is, put in the same screen). Photographing objectsabove water and objects under water simultaneously is referred to as“semi-underwater photographing.”

When the user 63 sets the camera 51C in a photographing state (posturestate) in a semi-underwater photographing mode as shown in FIG. 47A andperforms an instruction/operation of turning ON the semi-underwaterphotographing mode button 56 c, the image processing & control section54 sets the camera 51C in an operation state in the semi-underwaterphotographing mode.

In FIG. 47A and FIG. 47B, reference character W denotes the watersurface, Wu denotes a portion on the above water side (that is, the airside) and Wi denotes a portion on the underwater side. Furthermore,reference character T denotes an object of a figure straddling abovewater and under water to be photographed in the semi-underwaterphotographing mode (for simplicity).

In the present embodiment, the image processing & control section 54 inFIG. 45 is configured to have each of the functions of an imagesynthesis section 54 a′, a display control section 54 b, a focusingcontrol section 54 c, a distance conversion section 54 d and a lowcontrast region detection section 54 f′ as will be described below.

Furthermore, the image processing & control section 54 is configuredusing, for example, a CPU and a memory 61 that stores a program toexecute the respective functions above and is connected to the imageprocessing & control section 54. The memory 61 is made up of anon-volatile memory such as flash memory. Furthermore, the imageprocessing & control section 54 is internally provided with a memory(not shown) such as RAM to temporarily store data and image data or thelike. The memory 61 may also function as such a memory.

When performing semi-underwater photographing as described above, theuser 63 sets a photographing state in a semi-underwater photographingmode in which most of the lower half portion of the photographing lens53 a (of the image pickup section 53) of the camera SIC is submerged inwater as shown in FIG. 47B.

The camera 51C shown in FIG. 47B is set in a state as shown in FIG. 48.In the state in the semi-underwater photographing mode set as shown inFIG. 48, substantially the lower half portion of the photographing lens53 a of the image pickup section 53 on the front side of the camera 51Cis submerged in water below the water surface.

Furthermore, FIG. 48 illustrates a situation in which the photographinglens 53 a of the image pickup section 53 achieves focus on, for example,an object on the above water side set in the semi-underwaterphotographing mode.

The photographing lens 53 a making up the image pickup section 53illustrated in FIG. 48 is allowed to move in the optical axis directionby the drive section 53 e making up the focusing section 53 d.Furthermore, the focusing section 53 d is provided with a positionsensor 53 f, which detects the position of the photographing lens 53 aset by the drive section 53 e and outputs the position information tothe focusing control section 54 e and the distance conversion section 54d of the image processing & control section 54.

As shown in FIG. 48, when focus is achieved, for example, on the figureobject T as an object on the above water side, focus under water isachieved on a (distance) position behind the figure object T due to arefractive index nw under water.

This case (state in which focus is achieved on a position behind thefigure object T under water) is inconvenient because this is thedirection in which focus on fish or the like in front of the figureobject T is less likely to be achieved. Furthermore, for reasons relatedto underwater transparency (transmissivity), a distant view is morelikely to become obscure under water than above water. For this reason,it is inconvenient to achieve focus on a distant object underwater siderather than the above water side.

Thus, in the present embodiment, the focusing control section 54 c ofthe image processing & control section 54 performs control such thatfocus is achieved (focus setting) at a shorter distance than the focusposition shown in FIG. 48.

FIG. 49 shows a state of the (photographing lens 53 a of the) imagepickup section 53 in which the focusing control section 54 c hasachieved focus. As shown in FIG. 49, the photographing lens 53 a is setat a position ahead of the position of the photographing lens 53 a shownin FIG. 48 (position indicated by the dotted line in FIG. 49).

By so setting, focus is achieved at a shorter distance than the focusposition in FIG. 48. FIG. 49 illustrates an approximate amount of blur Uas the amount of deviation of the image formed on the image pickupdevice 53 b through the optical path on the above water side from theimage focused on the underwater side from a position above water.

The focusing processing method here is as shown in FIG. 50. When thefocusing in the semi-underwater photographing mode starts, the focusingcontrol section 54 e of the image processing. & control section 54drives the drive section 53 e of the focusing section 53 d in first stepS301 and moves the photographing lens 53 a in the optical axisdirection.

During the movement, the image processing & control section 54 detects acontrast signal corresponding to a difference between a brightnesssignal of the brightest portion and a brightness signal of the darkestportion obtained from each frame of the image pickup signal of the imagepickup device 53 b.

In step S302, the image processing & control section 54 sets thephotographing lens 53 a at a position where the contrast signal reachesa peak. The set position is detected by the position sensor 53 f and theposition sensor 53 f sends the position information to the distanceconversion section 54 d.

In next step S303, the distance conversion section 54 d calculates adistance (referred to as “object distance”) L to the focused object fromthe position information.

Furthermore, in next step S304, the distance conversion section 54 dcalculates a distance on the shorter distance side than the obtainedobject distance L as a focusing distance Lh which is actually focused inconsideration of the refractive index of water nw (=1.33).

In this case, the distance conversion section 54 d of the imageprocessing & control section 54 determines the focusing distance Lh fromL/C using a correction coefficient C (e.g., C=1.3 as a default value, aswill be described in FIG. 54) provided beforehand for the objectdistance L.

In other words, the distance conversion section 54 d converts the objectdistance L obtained on the above water side to the focusing distance Lhappropriate for clearly (picking up images of) photographing bothobjects above water and under water.

The distance conversion section 54 d then sends the focusing distance Lhto the focusing control section 54 c and ends the processing ofcalculating the focusing distance Lh in FIG. 50.

Therefore, when performing focusing while the semi-underwaterphotographing mode is set, the focusing control section 54 c in thepresent embodiment calculates the object distance L to the object abovewater and performs control of setting the focus position for performingfocusing in consideration of the refractive index under water.

Though aforementioned FIG. 49 or the like illustrates a case where theheight of the water surface W is not fluctuating, the height of thewater surface W may actually locally fluctuate due to wind or the likeand a wave 81 may be generated. FIG. 51 illustrates a situation in whichthe generation of the wave 81 affects the object image to bephotographed formed on the image pickup plane of the image pickup device53 b.

As shown in FIG. 51, the light impinging on the photographing lens 53 afrom the object side is substantially obstructed by a portion where thewater surface W turns from a crest to a trough of the wave 81, that is,the water surface section of a region 82 shown by hatching in FIG. 51and is prevented from forming an image on the image pickup device 53 b.

FIG. 51 shows the state in which fluctuations of the water surface Waffect some region of the image pickup plane of the image pickup device53 b, and in cases as shown in FIG. 52A and FIG. 52B where there is awave 81 larger than the lens diameter of the photographing lens 53 a (ofthe image pickup section 53), the region receives greater influences.

FIG. 52A illustrates a state in which the wave 81 approaches its troughimmediately before the photographing lens 53 a. This is a state in whichthe photographing lens 53 a faces the air above the water surface W. Inthis state, the portion shown by hatching immediately before thephotographing lens 53 a where the wave 81 goes from its trough to itscrest corresponds to a region that obstructs image pickup of the object(to be photographed) (that is, a region where the image is out of focus,and picked up obscurely in a low contrast state, and therefore theobject to be photographed is photographed obscurely or image pickup isimpossible or the age is lost) 82 a. θ denotes the field of view of theimage pickup section 53 of the camera 51C.

In this case, an image acquired from the object image formed on theimage pickup plane of the image pickup device 53 b (of the image pickupsection 53) or an image IA which is the image displayed on the displaysection 55 is as shown in FIG. 53A.

As shown in FIG. 53A, part of the object above water of the upperportion of the field of view θ of the camera 51C due to the region 82 a(water surface section where the height of the water surface Wfluctuates) shown in FIG. 52A can be acquired as an image A throughimage pickup, whereas due to the region 82 a, an image region 82 b isgenerated in the lower portion thereof as a water surface pattern (watersurface section image) which is an image of the object to bephotographed picked up obscurely with low contrast.

In other words, in an image picked up of the original object to bephotographed, the image region 82 b is generated whose image is pickedup with low contrast due to the water surface section where the heightof the water surface W locally fluctuates. As will be described later,the image region 82 h is detected as a water surface pattern (image ofthe water surface section) with low contrast.

Furthermore, FIG. 52B illustrates astute in which the camera 51C issubmerged under a crest of the wave 81. In this state, the portion shownby hatching becomes a region 82 c that obstructs image pickup of theobject to be photographed. In this case, an image IB that can beacquired is as shown in FIG. 53B.

As shown in FIG. 53B, part of the object under water of the lowerportion of the field of view θ of the camera 51C due to the region 82 cshown in FIG. 52B can be acquired as an image B through image pickup,whereas due to the region 82 c, an image region 82 d is generated in theupper portion thereof as a water surface pattern which is an image ofthe object to be photographed picked up obscurely with low contrast.

The image synthesis section 54 a′ of the image processing & controlsection 54 of the present embodiment then generates a synthesized imagethat interpolates at least one of the image of the object above waterand the image of the object under water whose photographing isobstructed by the water surface section. To be more specific, the imagesynthesis section 54 a′ performs image synthesis processing ofgenerating a synthesized image IC shown in FIG. 53C by synthesizing theimage IA in FIG. 53A with the image IB in FIG. 53B. The display controlsection 54 b outputs the synthesized image IC generated by the imagesynthesis section 54 a′ to the display section 55 and the displaysection 55 displays the synthesized image IC shown in FIG. 53C.

The synthesized image IC shown in FIG. 53C is synthesized by placing theregion other than the low contrast region on the upper portion of theimage IB (that is, image B) in the image region 82 b which is the lowcontrast region in the lower portion of the image IA. In this case,although the water surface pattern corresponding to the vicinity of thewater surface alone remains in the center region, the synthesized imageIC is obtained above and below the center region, that simultaneouslyaccommodates the (above water object) image A corresponding to theobject above water and the (under water object) image B corresponding tothe object under water.

Since the time difference between photographing timings at which theimage IA and the image IB are acquired respectively can be normallyestimated to be small, the variation in the field of view by the imagepickup section 53 is ignored and both images can be considered to be inthe same photographing state. The present embodiment then performs imagesynthesis of generating the synthesized image IC shown in FIG. 53C bysubstituting or interpolating the image region 82 b of the low contrastregion corresponding to the lower portion of the image IA in FIG. 53Awith the image B in the image IB in FIG. 53B.

In other words, the present embodiment includes the image synthesissection 54 a′ that performs interpolation (including a case ofsubstitution), when an object above water and an object under water arephotographed in the photographing state in a semi-underwaterphotographing mode, if an image of one of the object above water and theobject under water cannot be acquired due to influences of the watersurface section whose water surface fluctuates, on the one image withthe other image that could be acquired or other images and generates asynthesized image.

In order to generate the synthesized image IC shown in FIG. 53C, theimage processing & control section 54 has the function of the watersurface section image detection section 54 e′ shown in FIG. 45 fordetecting the image region 82 b or 82 d in each image in FIG. 53A andFIG. 53B obscurely picked up as an image of the water surface sectionwhich is an image of the water surface section whose water surfacefluctuates.

The water surface section image detection section 54 e′ includes thefunction of the low contrast region detection section 54 f′ that detectsa low contrast region as a region having low contrast as acharacteristic of the water surface section. In the present embodiment,the water surface section is mainly applied to the case of a watersurface that fluctuates, but there can also be a case where the watersurface does not fluctuate.

The low contrast region detection section 54 f′ determines by comparisonwhether the brightness value of each pixel of an image picked up by theimage pickup device 53 b is equal to or less than a predeterminedthreshold and detects a pixel region whose brightness value is equal toor less than the threshold as a low contrast region which has a highprobability of being the image of the water surface sectioncorresponding to the water surface section.

When the determination result shows that the detected low contrastregion satisfies a predetermined condition which will be described laterin FIG. 55, the water surface section image detection section 54 e′determines that the low contrast region is the image of the watersurface section (water surface pattern).

Furthermore, the image states in FIG. 53A and FIG. 53B corresponding toFIG. 52A and FIG. 52B vary with time. Thus, the present embodimenttemporally monitors a variation in brightness (contrast) in the upperand lower portions of the image acquired through image pickup.

The camera 51C has the feature of including the image pickup section 53for simultaneously photographing an object above water in the upperportion of the water surface and an object under water in the lowerportion of the water surface, the water surface section image detectionsection 54 e′ that detects an image of the water surface sectioncorresponding to the water surface section on the boundary between an(object above water) image of an object above water and an (under waterobject) image of an object under water and the image synthesis section54 a′ that generates a synthesized image for interpolating at least oneof the (above water object) image and (under water object) image whosephotographing is obstructed by the presence of the water surface sectionwithin the field of view of the image pickup section 53 based on thedetection result of the image of the water surface section.

Furthermore, the camera 51C has the semi-underwater photographing modedetermining section 54 g that automatically detects that the imagepickup section 53 is set to a photographing state in a semi-underwaterphotographing mode as the photographing mode for simultaneouslyphotographing an object above water and an object under water and theimage synthesis section 54 a′ has the function of detecting an image ofthe water surface section generated from the water surface section whosewater surface fluctuates from a plurality of images photographed by theimage pickup section 53 at a plurality of photographing timings afterthe determination of the photographing state in/be semi-underwaterphotographing mode by the semi-underwater photographing mode determiningsection 54 g, synthesizing an (above water object) image of the objectabove water or an (under water object) image of the object under waterwith at least part of the image of the water surface section andgenerating a synthesized image with the reduced region of the image ofthe water surface section.

Next, with reference to FIG. 54, the processing procedure forphotographing and recording, and generating and displaying a synthesizedimage mainly by the image processing & control section 54 of the camera51C if the present embodiment will be described.

When the photographing operation starts, the image processing & controlsection 54 determines in first step S211 whether or not the user 63 setsa photographing mode. When the photographing mode is set, the imageprocessing & control section 54 performs image processing for displayingthe image picked up by the image pickup section 53 on the displaysection 55 in next step S212, outputs the image to the display section55 and the display section 55 displays the image as a through image (asthe image of the object picked up by the image pickup device 3 b).

In next step S213, the image processing & control section 54 determineswhether or not the camera 51C is set to the photographing state in thesemi-underwater photographing mode. If this determination is set to beperformed by an automatic determination, such an automatic determinationon the photographing state in the semi-underwater photographing mode ismade according to a processing procedure in FIG. 56 which will bedescribed later.

When the photographing state in the semi-underwater photographing modeis not set, as shown in step S214, the focusing, control section 54 c ofthe image processing & control section 54 performs focusing in thecenter of the screen. After that, in next step S215, the imageprocessing & control section 54 performs processing of normalphotographing and then moves to processing in step S211.

On the other hand, when it is determined in step S213 that thephotographing state in the semi-underwater photographing mode is set,the focusing control section 54 c of the image processing & controlsection 54 performs focusing in the upper portion of the screen in stepS216 and determines exposure in the lower portion of the screen.

The image processing & control section 54 performs processing such asfocusing on the object image formed on the image pickup plane of theimage pickup device 53 b (e.g., the image of the object is formed upsidedown on the image pickup plane), but a case where the object image isdisplayed on the screen of the display section 55 while keeping theactual longitudinal position of the object will be described as areference.

That is, the focusing control section 54 c performs focusing based on animage pickup signal (image signal obtained by picking up an image of theobject on the above water side and calculates (detects) theaforementioned object distance L. On the other hand, regarding exposure,the focusing control section 54 c determines exposure so that brightnessappropriate for photographing of the object on the underwater side isobtained.

Furthermore, the present embodiment performs control processing ofsetting the focusing distance Lh so as to be able to clearly photographalso the object under water as described above.

In next step S217, the distance conversion section 54 d of the imageprocessing & control section 54 performs a conversion that converts theobject distance L to the focusing distance Lh for actual focusing. To bemore specific, the distance conversion section 54 d calculates thefocusing distance Lh by dividing the object distance L by 1.3 as acorrection coefficient C. That is, the distance conversion section 54 dsets Lh=L/1.3. The focusing control section 54 c then sets thephotographing lens 53 a at the focus position of this focusing distanceLh.

The process then moves to processing in step S218. The photographingstate of the image pickup section 53 set through the processing in stepS217 corresponds to the state shown in FIG. 49.

Such a setting is based on the consideration that a balance in focusbetween fish in front of the body portion under water of the figureobject T and the body portion above water improves (focuses on bothobjects are balanced, thus preventing such focusing that one of thoseimages becomes obscure).

Though C=1.3 is assumed as the correction coefficient C in the abovecase, if the body portion above water and the body portion below thewater surface are assumed to be the main photographing targets insteadof assuming fish under water as the main photographing targets, thefocusing distance Lh may be set to on the order of L/1.2.

Thus, the correction coefficient C may be set, for example, to C=1.3 asthe default value and the user 63 may be allowed to change the value ofthe correction coefficient C within a range of on the order of 1.1 to1.3 through a selection operation.

Furthermore, the object under water may turn darker (due to transparencycompared to the above water side), may have lower contrast or may besusceptible to influences of suspended solids or the like, and thereforein step S216, focusing is performed on the object above water which hashigher reliability so as to be able to calculate the object distance Lwhich has higher reliability (accuracy).

Furthermore, in photographing such a scene, assuming that there is anobject to be photographed under water, control is performed so as todetermine exposure based on the brightness of the object on theunderwater side. Furthermore, the region may be divided into under waterand above water portions, and the image processing & control section 54may change the amplification factors (gains) when performing imageprocessing so as to obtain appropriate brightness for both regions.

In step S218, the image processing & control section 54 determineswhether or not a release operation is performed. When the releaseoperation is not performed, the process returns to the processing instep S211.

On the other hand, when the release operation is performed, in next stepS219, the water surface section image detection section 54 e′ of theimage processing & control section 54 detects whether or not there isany generation of an image region that is lost due to the water surfacesection as shown in FIG. 53A or FIG. 53B, that is, detects whether ornot a water surface pattern (image of the water surface section) hasbeen generated.

In next step S220, the water surface section image detection section(water surface pattern detection section) 54 e′ determines whether ornot a water surface pattern exists in the center part and the lowerportion of the screen is a low contrast region using the function of thelow contrast region detection section 54 f′.

When the determination result is affirmative, in next step S221, theimage processing & control section 54 designates the determined image asan image IA, adds date and time information from the clock section 59thereto, performs photographing and records the image in the recordingsection 58. The process then returns to the processing in step S220.

On the other hand, when the determination result in step S220 isnegative, the process also moves to processing, in step S222.

In step S222, the water surface section image detection section 54 e′determines whether or not the water surface pattern exists in the centerpart and the upper portion of the screen is a low contrast region usingthe function of the low contrast region detection section 54 f′.

When this determination result is affirmative, in next step S223, theimage processing & control section 54 designates the determined image asan image IB, adds date and time information from the clock section 59thereto, performs photographing and records the image in the recordingsection 58. The process then returns to the processing in next stepS222.

On the other hand, when the determination result in step S222 isnegative, the process moves to processing in step S224.

When the image IA is recorded in the recording section 58, in step S224,the image synthesis section 54 a of the image processing & controlsection 54 generates a synthesized image IC by synthesizing an image ina region other than the low contrast region of the image IB with the lowcontrast region of the image IA. The display control section 54 bperforms control over the display of the synthesized image IC on thedisplay section 55 and the display section 55 displays the synthesizedimage IC as shown in FIG. 53C.

Therefore, as shown in FIG. 53A or FIG. 53B, even when photographing isperformed at timing at which only part of the intended object to bephotographed can be photographed, the present embodiment displays asynthesized image IC expressing substantially the whole picture of theobject obtained by synthesizing images photographed at a plurality oftimings on the display section 55 as shown in FIG. 53C, and thereforethe user 63 can observe the synthesized image IC.

After the processing in step S224, the process returns to the processingin first step S211. The image processing & control section 54 may recordthe synthesized image IC in the recording section 58 according to asetting by the user 63.

On the other hand, when the photographing mode is not set in step S211,the image processing & control section 54 determines in step S225whether or not the reproducing mode is set. When the reproducing mode isnot set, the process moves to step S227.

When the determination result in step S211 shows that the reproducingmode is set, the image processing & control section 54 reproduces theimage recorded in the recording section 58 in step S226. In next stepS227, the image processing & control section 54 determines whether ornot an end operation is performed. When the end operation is notperformed, the process returns to the processing in step S211, whereaswhen the end operation is performed, the power of the camera 51C isturned OFF and the processing in FIG. 54 ends.

FIG. 55 illustrates an example of the water surface pattern detectionprocessing procedure in step S219 in FIG. 54. When the water surfacepattern detection processing starts, the water surface section imagedetection section 54 e′ of the image processing & control section 54determines in first step S231 whether or not a contrast variation equalto or above a predetermined value exists in the center of the screen.

In this case, the water surface section image detection section 54 e′ ofthe image processing & control section 54 identifies (determines) thelongitudinal direction of the camera 51C according to the direction ofgravity acceleration detected by the acceleration sensor. The watersurface section image detection section 54 e′ then determines whether ornot there is a contrast variation equal to or above the predeterminedvalue near the center part in the vertical direction of the screen.

When a water surface which becomes a water boundary (water surfacesection) exists in the center of the screen, there is a variation incontrast between the underwater side that absorbs light and the abovewater side that less absorbs light across the water surface as theboundary. The water surface section image detection section 54 e′ thendetermines the contrast variation.

In next step S232, the water surface section image detection section 54e′ determines the boundary of the contrast variation or a range in thehorizontal direction of the contrast region (as a low contrast region)of the portion where the contrast variation exists.

In next step S233, the water surface section image detection section 54e′ determines whether or not the low contrast region exists in a handshape in the horizontal direction (like the water surface).

When the determination result shows that the low contrast region existsin a band shape in the horizontal direction, the water surface sectionimage detection section 54 e′ determines in next step S234 whether ornot there is a contrast difference between the upper and lower portionsof the screen.

When the determination result shows that there is a contrast differencebetween the upper and lower portions of the screen, the water surfacesection image detection section 54 e′ determines the low contrast regionthat meets the conditions in step S233 and S234 as a water surfacepattern (water surface section image) in step S235 and ends theprocessing in FIG. 55.

On the other hand, when the determination result in step S233 isnegative and the determination result in step S234 is negative, thewater surface section image detection section 54 e′ determines that thelow contrast region does not correspond to the water surface pattern andends the processing in FIG. 55. When the processing in FIG. 55 ends, theprocess moves to processing in step S220 in FIG. 54. Furthermore, theprocessing procedure in step S213 in FIG. 54 for automaticallydetermining whether or not the photographing state is in thesemi-underwater photographing, mode is as shown in FIG. 56.

When the processing of determining whether or not the photographingstate is in the semi-underwater photographing mode starts, the imageprocessing & control section 54 determines in first step S241 whether ornot the low contrast region exists in the center of the screen. When thedetermination result shows that the low contrast region exists, theimage processing & control section 54 determines the upper and lowerportions of the screen in next step S242.

In this case, the image processing & control section 54 determines theupper and lower portions using the detection result by the accelerationsensor.

After that, the image processing & control section 54 determines in stepS243 whether or not the low contrast region crosses the screen in thehorizontal direction in a band shape. When the determination result isaffirmative, the image processing & control section 54 determines innext step S244 whether or not the camera 51C has tipped over using thedetection result of the acceleration sensor.

When performing semi-underwater photographing using the camera 51C shownin FIG. 45A and FIG. 45B, the user 63 holds the camera 51C in a posturein which the photographing lens 53 a comes to a lower position than thecenter of the camera 51C as shown in FIG. 52A or FIG. 52B.

Furthermore, in the case of the camera 51C, the user 63 sets thelongitudinal direction of the camera 51C to the vertical direction inwhich gravity acts. FIG. 57B illustrates the posture of the camera 51Ccorresponding to FIG. 52A.

In this case, the image processing & control section 54 determineswhether or not the camera 51C has tipped over using an accelerationsensor 65 a shown by a dotted line and a detection result by anacceleration sensor (not shown) that detects acceleration in the lateraldirection of the plane of the sheet which is perpendicular to thevertical direction detected by the acceleration sensor 65 a.

FIG. 57B illustrates a state in which the longitudinal direction of thecamera 51C has no tipping (inclination) parallel to the verticaldirection, and on the other hand. FIG. 57C and FIG. 57D illustrate astate in which there is tipping (inclination) in a clockwise directionand a counterclockwise direction.

When the determination result shows that there is no tipping as in thecase of FIG. 57B, the image processing & control section 54 determinesin step S245 that the camera 51C in this state is in the photographingstate in the semi-underwater photographing mode and ends the processingin FIG. 56.

On the other hand, when the determination result in step S241 isnegative, the determination result in step S243 is negative and thedetermination result in step S244 is negative, the image processing &control section 54 determines in step S246 that the camera 51C in thisstate is not in the photographing state in the semi-underwaterphotographing mode and ends the processing in FIG. 56.

After determinations in step S245 and step S246 in FIG. 56, displayswitching (by the display section 55) according to the determinationresult may also be performed as shown in step S247. Information may bedisplayed on the display section 55.

FIG. 58 illustrates the processing procedure in this case. When thedisplay switching processing starts, the image processing & controlsection 54 determines in first step S261 whether or not thephotographing state is in the semi-underwater photographing mode.

When the determination result shows that the photographing state is inthe semi-underwater photographing mode, the image processing & controlsection 54 displays the mode of the determination result, for example, adisplay indicating “semi-underwater photographing mode” in, for example,the upper half portion of the display section 55 as shown in FIG. 57A innext step S262. The image processing & control section 54 then ends thedisplay switching processing.

On the other hand, when the determination result in step S261 shows thatthe photographing state is not in the semi-underwater photographingmode, in next step S263, the image processing & control section 54performs a normal image display (that is, a normal image is displayed infull screen on the display plane of the display section 55) and ends thedisplay switching processing.

With such a display, the user 63 can confirm that the photographingstate is set in the semi-underwater photographing mode. Such a displaycan improve operability for the user 63.

As a modification example of the processing procedure for determiningthe photographing state in the semi-underwater photographing mode shownin FIG. 56, a processing procedure shown in FIG. 59A may be adopted. Theprocessing procedure in this modification example determines thephotographing state in the semi-underwater photographing mode anddetermines a water surface pattern in the determining processingprocedure as well. For this reason, when the processing procedure isapplied to FIG. 54, it is possible to move to processing in next stepS220 using the above described determination result when performing thewater surface pattern detection processing next to step S218.

When the determining processing on the photographing state in thesemi-underwater photographing mode shown in FIG. 59A starts, the imageprocessing & control section 54 determines in first step S271 whether ornot there is any contrast variation in the center of the screen. In thiscase, the image processing & control section 54 identifies (determines)the vertical direction of the camera 51C according to the direction ofgravity acceleration by the acceleration sensor. The image processing &control section 54 then determines whether or not there is any contrastvariation near the center in the vertical direction of the screen.

When there is a water surface which becomes a boundary of water in thecenter of the screen, a contrast variation occurs between the underwaterside that absorbs light and the above water side that less absorbs lightacross the water surface as the boundary.

When it is determined that there is a contrast variation in the centerof the screen, the image processing & control section 54 determines innext step S272 whether or not the boundary of the contrast variationcrosses the screen in the horizontal direction (lateral direction). Inthe case of the water surface, the boundary of the contrast variationcrosses the screen.

When the determination result shows that the boundary of the contrastvariation crosses the screen, the image processing & control section 54performs processing of comparing contrast between the upper and lowerportions of the screen in next step S273. The image processing & controlsection 54 determines (identifies) (the posture of) the upper and lowerportions of the screen from the signal of the acceleration sensor inthis case, too.

In next step S274, the image processing & control section 54 determineswhether or not there is a dark low contrast region with low contrast inthe lower portion (that is, whether or not the lower portion constitutesa low contrast region). In this case, instead of determining the lowcontrast region, it may be possible to simply determine whether or notthe lower image is darker than the upper image. In the case of theobject as shown in FIG. 59B, the underwater side in the lower portion isdarker.

When the determination result shows that the lower portion is darker,the image processing & control section 54 compares color tones betweenthe upper and lower portions of the screen in next step S275. In nextstep S276, the image processing & control section 54 determines whetherthe red component in the lower portion is smaller than that in the upperportion.

When the red component in the lower portion is smaller than that in theupper portion, the image processing & control section 54 determines instep S277 that the photographing state is set in the semi-underwaterphotographing mode. Furthermore, as shown in step S279, the imageprocessing & control section 54 determines the boundary of the contrastvariation as a water surface pattern.

The image processing & control section 54 then moves to processing instep S216 in FIG. 54.

On the other hand, when determinations in steps S271, S272, S274 andS276 are negative, the image processing & control section 54 determinesin step S278 that the photographing state is not in the semi-underwaterphotographing mode and moves to processing in step S214 in FIG. 54.

The determination in step S277 or S278 may also be made from thedetermination result of one of two determining processes in step S274and S276.

According to the processing in FIG. 59A, it is possible to determinefrom the determination result in step S277 that the portion where theboundary of the contrast variation in the center of the screen in stepS272 crosses the screen is a water surface pattern, and determine(identify) that the upper portion thereof is an object above water andthe lower portion thereof is an object under water.

FIG. 59B is a diagram illustrating the determination of thesemi-underwater photographing mode in FIG. 59A and FIG. 59B illustratesa typical example of object in the photographing state in thesemi-underwater photographing mode.

As shown in FIG. 59B, the under water region has lower transparency thanthat above water region, is darker due to absorption of light and oftenincludes suspended solids, thus constituting a low contrast region withlow contrast.

Furthermore, the wavelength of red light on the long wavelength side inthe visible region in particular is more easily absorbed than the shortwavelength side and is more likely to have blue color tone (in otherwords, color tone with less red component). Therefore, the processingprocedure in FIG. 59A can be used to determine the semi-underwaterphotographing mode.

The camera 51C according to the eighth embodiment that performs such anoperation synthesizes a plurality of images photographed atphotographing timings at which objects above water or objects underwater are lost or photographing is not possible due to the water surfacesection whose water surface W fluctuates, and can thereby generate asynthesized image simultaneously including objects above water andobjects under water.

Therefore, the user 63 can acquire a synthesized image as an image ofexcellent image quality simultaneously including objects above water andobjects under water with reduced influences of variations of the watersurface W and observe (appreciate) the image of excellent image quality.

Ninth Embodiment

FIG. 60 illustrates a configuration of a portable camera section (simplyreferred to as “camera section” in the FIG. 51D according to a ninthembodiment of the present invention. The portable camera section 51D ofthe present embodiment is mounted on a cellular phone 151 having awaterproof function as shown in FIG. 61. The cellular phone 151 is madeup of a portable camera section 151B and a display section 55, which areindependent bodies, and the portable camera section 151B and the displaysection 55 are foldably connected together by a folding section.

The portable camera section 51D shown in FIG. 60 corresponds to thecamera 51C shown in FIG. 45 further provided with a temporary recordingsection 54 h in the image processing & control section 54 that has arecording capacity for recording at least a plurality of images fortemporarily recording (storing) images picked up for a predeterminedperiod. Temporarily recording images also refers to “temporaryrecording.” Furthermore, when an image is temporarily recorded in thetemporary recording section 54 h, timing at which the image istemporarily recorded is recorded simultaneously.

Furthermore, an image processing & control section 54 of the presentembodiment has the function of a photographing timing determiningsection 54 i that determines photographing timing at which imagesconsidered substantially excellent in a semi-underwater photographingmode are recorded (photographed and recorded) in a recording section 58as photographed images.

Upon detecting a low contrast region in images picked up, a low contrastregion detection section 54 f′ temporarily records the images in thetemporary recording section 54 h. The temporarily recorded images arepassed through an image synthesis section 54 a′ and a display controlsection 54 b, and images determined to be excellent are displayed on adisplay section 55.

FIG. 61 illustrates a situation in which a user 63 is picking up animage of a turtle swimming near the water surface of a pond 153 as anobject of appreciation using the cellular phone 151 provided with theportable camera section 51D in the configuration shown in FIG. 60.

As shown in FIG. 61, the user 63 can set the center position of aphotographing lens 53 a (of an image pickup section 53) of the portablecamera section 51D in the vicinity of the water surface and set aphotographing state in a semi-underwater photographing mode in whichobjects above water and objects under water of the pond 153 arephotographed.

As described in aforementioned FIG. 51, the region 82 shown by hatchingwhere the water surface W fluctuates substantially interferes with imageformation of the object images within the field of view θ. Thus, whenthe image picked up in the photographing state in FIG. 61 and acquiredat certain image pickup timing is displayed on the display section 55,an image IC′ as shown in FIG. 62A is obtained.

In this case, a water surface pattern (image of the water surfacesection) of a low contrast region is generated in the vicinity of thecenter, and the upper and lower portions thereof become an (above waterobject) image of the object above water and an (under water object mageof the object under water.

When there is a situation in which the water surface W temporallyfluctuates due to wind or the like, depending on image pickup timings,the image becomes an image of poor quality such as images IA′ and IB′shown in FIG. 62B and FIG. 62C compared to an image IC′ in FIG. 62A.Thus, the present embodiment is designed to display nothing in the casesof the images in FIG. 62B and FIG. 62C and to be able to display abetter image or better synthesized image as the image in FIG. 62A.

Actually, processing is necessary to determine whether these images areexcellent images or not excellent images considerably affected by awater surface pattern. Thus, in the meantime until the determinationresult is confirmed, the images such as those in FIG. 62B and FIG. 62Cmay also be temporarily displayed.

Upon detecting a low contrast region, the image processing & controlsection 54 temporarily records the image in the temporary recordingsection 54 h. The image processing & control section 54 then performscontrol of displaying the image on the display section 55 according to adisplay control processing procedure shown in FIG. 63.

When the display control processing in FIG. 63 starts, in first stepS201, the image processing & control section 54 captures an image of anobject picked up by the image pickup section 53. In next step S202, thelow contrast region detection section 54 f′ of the image processing &control section 54 detects a low contrast region in the picked up image.

The low contrast region detection section 54 f′ then determines whetheror not the detected low contrast region is only the center part of thescreen (in the vertical direction) as shown in FIG. 62A. When makingsuch a determination, the image processing & control section 54recognizes the vertical direction of the screen using the detectionresult by an acceleration sensor. Whether or not the detected lowcontrast region is only the center part is determined depending, onwhether or not the width in the vertical direction of the low contrastregion having low contrast, that is, the width of the band pattern inthe horizontal direction formed by the low contrast region is equal toor below a predetermined value (or a threshold). When the width is equalto or below the predetermined value, the image is determined to be anexcellent image.

When the determination result shows that the low contrast region is notonly the center part, the image processing & control section 54determines in next step S203 whether or not the upper portion of thescreen is the low contrast region, that is, whether or not the lowcontrast region extends upward as shown in FIG. 62B.

When the determination result shows that the upper portion of the screenis the low contrast region, in next step S204, the image processing &control section 54 temporarily records the image in the temporaryrecording section 54 h as the image IA′ and moves to processing in stepS210 a.

FIG. 62B illustrates an example of the image IA′. In this case, togetherwith the image A′ of the object under water of the lower portion, theupper portion becomes the image IA′ where an image region 82 e which isa low contrast region is generated as an image of the water surfacesection (water surface pattern) by the water surface section.

On the other hand, when the determination result in step S203 shows thatthe upper portion of the screen is not the low contrast region, theimage processing & control section 54 determines in step S205 whether ornot the lower portion of the screen is the low contrast region, that is,determines whether or not the low contrast region extends downward asshown in FIG. 62C.

When the determination result shows that the lower portion of the screenis the low contrast region, the image processing & control section 54temporarily records the image in the temporary recording section 54 h asan image IB′ in next step S206. FIG. 62C illustrates an example of theimage IB′. In this case, together with an image B′ of the object underwater in the upper portion, the lower portion becomes the image IB′where an image region 82 f which is a low contrast region is generatedas an image of the water surface section (ater surface pattern) by thewater surface section.

In next step S207, the image processing & control section 54 generates asynthesized image by synthesizing the low contrast region of the imageIA′ temporarily recorded in the temporary recording section 54 h withthe image portion in a region other than the low contrast region of theimage IB′ and displays the synthesized image on the display section 55.

When the image IB′ in FIG. 62C is synthesized with the image IA′ in FIG.62B, the resulting image is a synthesized image similar to that shown inthe image IC′ shown in FIG. 62A.

Thus, when the image is determined not to be an excellent image, anexcellent image is generated and displayed by synthesizing a pluralityof temporarily recorded images. To be more specific, an excellent imageis generated and displayed by performing interpolation whereby from theimage IA′ in which the low contrast region extends upward and the imageIB′ in which the low contrast region extends downward, one low contrastregion is substituted by an image in the region other than the lowcontrast region in the other image.

Therefore, even in a situation in which no excellent images can bepicked up, the user 63 can observe (appreciate) an excellent image.

After the processing in step S207, the image processing & controlsection 54 moves to processing in step S210 a.

When the determination result in step S205 shows that the upper portionof the screen is not the low contrast region, in step S208, the imageprocessing & control section 54 moves to processing in step S210 awithout displaying the image.

Furthermore, the determination result in step S202 shows that the lowcontrast region exists only in the center part, the image processing &control section 54 temporarily records the image in the temporaryrecording section 54 h in step S209. The image IC′ in FIG. 62A is anexample of image corresponding to this case.

In next step S110 b, the image processing & control section 54 displaysthe image temporarily recorded in the temporary recording section 54 hon the display section 55 as is (because it is an excellent image). Theimage processing & control section 54 then moves to processing in stepS210 a.

In step S210 a, the image processing & control section 54 determineswhether or not a display end operation is performed. When the displayend operation is not performed, the image processing & control section54 returns to step S201, captures the next image and performs similarprocessing. On the other hand, when the display end operation isperformed, the processing in FIG. 63 ends.

According to the flowchart shown in FIG. 63, a processing procedure forprocessing of generating and displaying the synthesized image in stepS207 after temporary recording of the image IB′ in step S206 is adopted,but the present invention is not limited to this processing procedure.

For example, when the image IA′ or image IB′ is temporarily recorded inthe temporary recording section 54 h, if the image IB′ or image IA′ tobe synthesized has already been temporarily recorded, a synthesizedimage may be generated and displayed.

To be more specific, after the processing in step S205 in FIG. 63, theprocess may move to step S207. However, in step S207, it is determinedwhether or not the image IB′ or image IA′ to be synthesized has alreadybeen temporarily recorded, and in the case where the image IB′ or imageIA′ has not already been temporarily recorded, the synthesized image isnot generated, and the process moves to step S111, and in the case wherethe image IB′ or image IA′ has already been temporarily recorded, thesynthesized image is generated and displayed.

Furthermore, the present invention is not limited to the case describedin step S207 shown in FIG. 63, but an image in a region other than thelow contrast region of the image IA′ may be synthesized with the lowcontrast region of the image IB′ and displayed.

FIG. 64 illustrates a timing chart of display control corresponding tosuch a processing procedure (which is the processing procedure in FIG.63 slightly modified) and the horizontal direction shows time t.Furthermore, reference character Tf denotes an image pickup cycle whenthe object image corresponding to one screen (frame) is picked up by theimage pickup section 53, which is set to be equal to the display cycle.

The top row (first row) illustrates (picked up images) images Cj, Aj andBj in order of times elapsed in the images IC′, IA′ and IB′ picked up bythe image pickup section 53 and incorporated in the image processing &control section 54, respectively. Parameters showing a time sequence ofpicked up images are j=1, 2, 3, . . . .

The second row illustrates images Cj and Dj actually displayed on thedisplay section 55. The image Cj corresponding to the image IC′ means animage considered excellent when the low contrast region is limited onlyto the center part.

On the contrary, since the images Aj and Bj are not so excellent as theimage Cj, the images Aj and Bj are not displayed as they are. The imageDj is a synthesized image obtained by synthesizing the images Aj and Bj(j may be different) and is an image displayed. Without being limited tothe example in FIG. 64, the display control section 54 b may control theimages Aj and Bj so as to be displayed on the display section 55 for ashort period of time. The third and fourth rows in FIG. 64 will bedescribed later.

When an image C1 is picked up as shown in FIG. 64, the image C1 isdisplayed from the next frame on the display section 55. The display ofthe image C1 continues until the next image C2 is displayed or until asynthesized image D1 is displayed.

In the example in FIG. 64, images A1 and A2 are picked up after theimage C2, but since an image B1 is not picked up yet (nor temporarilyrecorded), the images A1 and A2 are not displayed. When the image B1 ispicked up, the synthesized image D1 (resulting from a synthesis of theimage B1 and the image A2) is displayed.

In this display example, when a synthesized image is displayed, if aplurality of the images Aj (to be more specific, the images A1 and A2)are temporarily recorded before the image Bj (B1, to be more specific),the image Aj is synthesized with the latest image (A2). When the image132 is picked up next to the image B1, the synthesized image D2 of theimage B2 and image A2 is displayed.

After that, an image C3 is picked up and the image C3 is displayed.After that, when an image A3 is picked up, a synthesized image D3 of theimage A3 and the latest image B2 before that time is displayed.Subsequent images will be displayed according to a similar rule.

With such display control, even in a situation in which an image of onlyan object above water or an image of only an object under water can bepicked up due to the presence of the water surface section, it ispossible to display a synthesized image simultaneously including theobject above water and object under water (the images D1 and D2 or thelike in FIG. 64) and an image assumed to simultaneously include theobject above water and object under water whose only center part becomesa low contrast region (the images C1 and C2 or the like in FIG. 64) canbe displayed on the display section 55.

Therefore, the user 63 can appreciate an image corresponding to a statein which an object image to be appreciated is picked up satisfactorily.

As a modification example of the display shown in FIG. 64, when asynthesized image is displayed, images with a small low contrast regionin the vertical direction, that is, images with small extension of a lowcontrast region in the vertical direction may be selected to generateand display a synthesized image.

Furthermore, a case has been described above where a picked up image isdisplayed. In the present embodiment, it is further possible to select aphotographing mode in which control over display andphotographing/recording are interlocked with each other.Photographing/recording in this case means not temporary recording butrecording an image in the recording section 58, and when such a meaningis obvious, photographing/recording is also simply referred to asphotographing or recording.

When control over display and photographing are interlocked with eachother in the present embodiment, it is possible to select a mode inwhich only an excellent image such as the aforementioned image C isphotographed/recorded or a mode in which a synthesized image is alsophotographed/recorded. Moreover, the present embodiment provides thetemporary recording section 54 h so as to be able to photograph/recordan excellent image such as the image C1 in the recording section 58without missing photographing timing.

In this case, such a portable camera section 51D is provided with theimage pickup section 53 for simultaneously photographing an object abovewater of the upper portion above the water surface and an object underwater of the lower portion below the water surface, the photographingtiming determining section 54 i that detects an image of the watersurface section generated by the water surface section whose watersurface fluctuates from the object image picked up by the image pickupsection 53 and determines photographing timing appropriate forsimultaneously photographing an (object above water) image of the objectabove water and an (object under water) image of the object under water,and the image synthesis section 54 a′ that generates a synthesized imagefrom a plurality of images of objects picked up at a plurality oftimings close to the photographing timing determined by thephotographing timing determining section 54 i.

To be more specific, the photographing timing determining section 54 iof the image processing & control section 54 temporarily records aplurality of images picked up by the image pickup section 53 during apredetermined period (during which the images can be recorded in thetemporary recording section 54 h) in the temporary recording section 54h together with the timings.

Furthermore, the photographing timing determining section 54 idetermines (judges) whether or not the image temporarily recorded in thetemporary recording section 54 h is a photographed image with a smallinfluence of the water surface section on the image of the water surfacesection or a photographed image to be photographed corresponding tosimultaneous photographing of the (object above water) image and the(object under water) image. The photographing timing determining section54 i then determines (designates as photographing timing) the timing ofphotographing/recording the determined photographed image from thetemporary recording section 54 h into the recording section 58 asphotographing timing for photographing a photographed image to bephotographed.

The image in which a low contrast region exists only in the center partof the screen as shown in FIG. 62A corresponds to the photographed imagein this case.

FIG. 65A illustrates a flowchart of part of a processing procedure whendisplaying and photographing are interlocked with each other.

FIG. 65A corresponds to a processing procedure for performing processingin step S321 and step S322 between step S210 b and step S210 a, forexample in the flowchart in FIG. 63. In step S210 b, after displayingthe images C1 and C2 or the like in FIG. 64 on the display section 55 asthey are, the image processing & control section 54 determines in stepS321 whether or not there is a setting (selection) that control overdisplay and control over photographing/recording are interlocked witheach other.

When control over display and control over photographing/recording areinterlocked with each other, the user 63 needs only to select“interlock” from a menu screen by operating, for example, the modesetting switch 56 b. The image processing & control section 54determines whether or not an interlock mode is set with reference to theselection result.

When the determination result shows that the interlock is not used, theimage processing & control section 54 moves to step S210 a after theprocessing in step S321. In this case, processing similar to that inFIG. 63 is performed.

On the other hand, when the determination result shows that theinterlock is used, in step S322 after the processing in step S321, theimage processing & control section 54 photographs an image whendisplayed on the display section 55, performs processing of recordingthe image in the recording section 58 and then moves to step S210 a. Therest is the same as FIG. 63 or the processing procedure with partsassociated with the generation and display of a synthesized image asdescribed above.

The photographing/recording following the processing procedure shown inFIG. 65A is shown on the third row in FIG. 64. The third row in FIG. 64shows photographing/recording (1). To be more specific, when the imageC1 considered to have excellent image quality whose low contrast regionis located only in the center part is displayed (as shown on the secondrow), as shown on the third row, the image C1 is photographed/recordedfrom the temporary recording section 54 h into the recording section 58as the photographed image to be photographed interlocked with thedisplay thereof.

In this case, together with the photographed image, the timing at whichthe image is temporarily recorded in the temporary recording section 54h or the timing at which the image is recorded in the recording section58 is recorded as the photographing timing. When the image C1 isconsecutively displayed, only the first image C1 isphotographed/recorded. For the following image C2 or the like,photographing/recording is performed interlocked with the display.

Therefore, in this case, the image processing & control section 54 hasthe function of the photographing timing determining section 54 i thatdetermines the photographing timing of photographing and recordinginterlocked with the image displayed on the display section 55 andconsidered to have excellent image quality. Furthermore, as describedabove, at timing close to this photographing timing (this timing mayalso defined so as to be included in the photographing timing), theimage synthesis section 54 a′ generates a synthesized image, and thesynthesized image generated is displayed on the display section 55.

Furthermore, in addition to photographing/recording of the images C1 andC2 or the like, synthesized images may be photographed/recorded. As anexample of this case, synthesized images D1, D2, . . . arephotographed/recorded interlocked with the display on the second row inFIG. 64. In addition, photographing/recording may also be performed asshown as photographing/recording (2) on the fourth row in FIG. 64. Inthe example shown on the fourth row, when a plurality of synthesizedimages are displayed consecutively, only a synthesized image generatedusing images with a low contrast region of the least extension in thevertical direction among those images is photographed/recorded.

In the specific example, when the image B1 is picked up, the synthesizedimage D1 of the image B1 and the latest image A2 which is temporarilyrecorded and not displayed is displayed, and in the next frame, thesynthesized image D2 of the image B2 and the image A2 is displayedconsecutively. In this case, the synthesized image D2 isphotographed/recorded assuming that this is a case where the extensionof the low contrast region in the vertical direction of the image B2 issmaller than that of the image B1. The timing at which the synthesizedimage D2 is actually recorded in the recording section 58 is after thedisplay of the synthesized image D2.

FIG. 65B illustrates a processing procedure for performing suchprocessing. The processing procedure in FIG. 65B corresponds to modifiedcontents of the processing procedure moving from step S206 to step S210a in FIG. 63.

After temporarily recording the image IB′ (the image B1 in FIG. 64) instep S206, the image processing & control section 54 determines in stepS331 whether or not the image IA′ is temporarily recorded in thetemporary recording section 54 h.

When the image IA′ is not temporarily recorded in the temporaryrecording section 54 h, the process moves to step S210 a, and on thecontrary, when the image IA′ is temporarily recorded in the temporaryrecording section 54 h, the process moves to step S332.

In step S332, the image processing & control section 54 generates asynthesized image from the image IB′ and the latest image IA′ which istemporarily recorded in the temporary recording section 54 h and notdisplayed, and displays the synthesized image. In this case, the imageprocessing & control section 54 synthesizes an image in a region otherthan the low contrast region of the latest image IA′ with the lowcontrast region of the image IB′, for example, and displays the image onthe display section 55. That is, the low contrast region of the imageIB′ is corrected through a substitution with the image (in a regionother than the low contrast region) of the image IA′, an excellent imageof the image IB′ with the reduced low contrast region is generated anddisplayed on the display section 55.

Furthermore, the image processing & control section 54 determines innext step S333 whether or not a plurality of images IB′ appearconsecutively and whether or not the image is the last image among theconsecutive images. When the determination result is negative, theprocess moves to step S210 a.

On the other hand, when the determination result in S333 is affirmative,the image processing & control section 54 detects IB′min, which is animage with the least expansion of the low contrast region in thevertical direction (to be more exact, downward direction from the centerpart) in next step S334. The image processing & control section 54 thenphotographs/records the synthesized image from the image IB′min and theimage IA′ and moves to step S210 a.

Since the last image of the consecutive images IB′ needs to be detected(determined) in order to detect the image IB′min, the above describedtiming of actually photographing/recording a synthesized image in therecording section 58 is slightly later than the image pickup timing ortemporary recording timing. However, when temporary recording isperformed, temporary recording timing (time) is simultaneously recordedtemporarily, and if those timings are recorded as photographing timings(times) at which the image is actually recorded in the recording section58, the slight delay of the actual recording operation constitutes noproblem. Furthermore, when the difference between the timing oftemporary recording and the timing of recording in the recording section58 is small, whichever timing may be used.

On the fourth row in FIG. 64, when the next images A3 and A4 are pickedup in sequence next to the image C3, processing (processing whereby IA′and IB′ are interchanged) similar to the processing shown in FIG. 65B isperformed.

Regarding the synthesized images D3 and 134, the synthesized image D4 islikewise photographed/recorded corresponding to the case using an imagehaving the least extension of the low contrast region in the verticaldirection. Here, the expansion of the low contrast region in thevertical direction for the image A4 is assumed to be smaller than thatof the image A3.

Thus, the ninth embodiment that controls display and photographing candisplay an image corresponding to such an excellent image pickup statethat simultaneously includes objects above water and objects underwater, and photograph/record such an image in the recording section 58in addition to the effects of the eighth embodiment.

The eighth embodiment may also determine whether or not, for example,the low contrast region in a synthesized image is smaller than athreshold in the vertical direction and record, when the determinationresult shows that the low contrast region is smaller than the threshold,the synthesized image as an excellent image in the recording section 58.Furthermore, a synthesized image determined to have little influence ofthe water surface section may be recorded in the recording section 58 asa photographed image.

Furthermore, embodiments configured by partially combining or modifyingthe aforementioned embodiments without departing from the spirit andscope of the invention also belong to the present invention.

What is claimed is:
 1. A waterproof camera comprising: an image pickupsection having a photographing lens and an image pickup device; afocusing section that achieves focus on an object image formed on animage pickup plane of the image pickup device by moving thephotographing lens or the image pickup device in an optical axisdirection of the photographing lens; a semi-underwater photographingmode setting section for setting a semi-underwater photographing mode inwhich photographing is performed by simultaneously accommodating anobject image above water which is an above water side and an objectimage under water which is an underwater side on the image pickup plane;and a focusing control section that controls focusing position by thefocusing section when the semi-underwater photographing mode is set soas to obtain a focus position corresponding to a distance from the imagepickup section to the object in consideration of a refractive indexunder and above the water.
 2. The waterproof camera according to claim1, wherein the focusing control section controls, when thesemi-underwater photographing mode is set, so as to realize a focusposition corresponding to a distance obtained by correcting the distancefrom the image pickup section to the object above water acquired throughfocusing by the focusing section on the object above water with acorrection coefficient corresponding to the refractive index underwater.
 3. The waterproof camera according to claim 2, wherein thefocusing control section controls, when the semi-underwaterphotographing mode is set, so as to further narrow down a brightnessdiaphragm of the image pickup section.
 4. The waterproof cameraaccording to claim 1, further comprising an image conversion sectionthat converts an image of an object picked up by the image pickupsection to a reduced image.
 5. The waterproof camera according to claim1, further comprising: a display section that displays an image pickedup by the image pickup section; an image conversion section thatconverts an image of an object picked up by the image pickup section toa reduced image; and a display control section that performs control soas to display the reduced image on the upper portion side of the displayscreen of the display section when the camera is set in a photographingposture.
 6. The waterproof camera according to claim 2, wherein thefocusing control section considers underwater transparency and performscontrol so as to perform focusing on the object under water when thesemi-underwater photographing mode is set and in the case of a conditionthat the distance to the object above water exceeds a predetermineddistance in consideration of the underwater transparency.
 7. Thewaterproof camera according to claim 1, further comprising anidentification section that identifies each image region of objectsabove water and objects under water from an image of an object picked upby the image pickup section.
 8. The waterproof camera according to claim2, further comprising a semi-underwater photographing mode determiningsection that performs image processing of determining whether or not aphotographing state is in a semi-underwater photographing mode in whichphotographing is performed by simultaneously accommodating an image ofan object above water which is the above water side and an image of anobject under water which is the underwater side on the image pickupplane from the image of the object picked up by the image pickupsection.
 9. The waterproof camera according to claim 1, wherein when thesemi-underwater photographing mode is set, the focusing control sectionperforms control so as to realize a focus position corresponding to adistance obtained by dividing the distance from the image pickup sectionto the object above water acquired through focusing by the focusingsection on the object above water by a refractive index n under water.10. The waterproof camera according to claim 6, wherein thepredetermined distance is approximately 3 meters.